2 This file is part of GNUnet.
3 Copyright (C) 2013 Christian Grothoff (and other contributing authors)
5 GNUnet is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published
7 by the Free Software Foundation; either version 3, or (at your
8 option) any later version.
10 GNUnet is distributed in the hope that it will be useful, but
11 WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 General Public License for more details.
15 You should have received a copy of the GNU General Public License
16 along with GNUnet; see the file COPYING. If not, write to the
17 Free Software Foundation, Inc., 59 Temple Place - Suite 330,
18 Boston, MA 02111-1307, USA.
22 #include "gnunet_util_lib.h"
24 #include "gnunet_signatures.h"
25 #include "gnunet_statistics_service.h"
27 #include "cadet_protocol.h"
28 #include "cadet_path.h"
30 #include "gnunet-service-cadet_tunnel.h"
31 #include "gnunet-service-cadet_connection.h"
32 #include "gnunet-service-cadet_channel.h"
33 #include "gnunet-service-cadet_peer.h"
35 #define LOG(level, ...) GNUNET_log_from(level,"cadet-tun",__VA_ARGS__)
36 #define LOG2(level, ...) GNUNET_log_from_nocheck(level,"cadet-tun",__VA_ARGS__)
38 #define REKEY_WAIT GNUNET_TIME_relative_multiply(GNUNET_TIME_UNIT_SECONDS, 5)
40 #if !defined(GNUNET_CULL_LOGGING)
41 #define DUMP_KEYS_TO_STDERR GNUNET_YES
43 #define DUMP_KEYS_TO_STDERR GNUNET_NO
46 #define MIN_TUNNEL_BUFFER 8
47 #define MAX_TUNNEL_BUFFER 64
48 #define MAX_SKIPPED_KEYS 64
49 #define MAX_KEY_GAP 256
50 #define AX_HEADER_SIZE (sizeof (uint32_t) * 2\
51 + sizeof (struct GNUNET_CRYPTO_EcdhePublicKey))
54 /******************************************************************************/
55 /******************************** STRUCTS **********************************/
56 /******************************************************************************/
60 struct CadetTChannel *next;
61 struct CadetTChannel *prev;
62 struct CadetChannel *ch;
67 * Connection list and metadata.
69 struct CadetTConnection
74 struct CadetTConnection *next;
79 struct CadetTConnection *prev;
84 struct CadetConnection *c;
87 * Creation time, to keep oldest connection alive.
89 struct GNUNET_TIME_Absolute created;
92 * Connection throughput, to keep fastest connection alive.
98 * Structure used during a Key eXchange.
100 struct CadetTunnelKXCtx
103 * Encryption ("our") old "confirmed" key, for encrypting traffic sent by us
104 * end before the key exchange is finished or times out.
106 struct GNUNET_CRYPTO_SymmetricSessionKey e_key_old;
109 * Decryption ("their") old "confirmed" key, for decrypting traffic sent by
110 * the other end before the key exchange started.
112 struct GNUNET_CRYPTO_SymmetricSessionKey d_key_old;
115 * Same as @c e_key_old, for the case of two simultaneous KX.
116 * This can happen if cadet decides to start a re-key while the peer has also
117 * started its re-key (due to network delay this is impossible to avoid).
118 * In this case, the key material generated with the peer's old ephemeral
119 * *might* (but doesn't have to) be incorrect.
120 * Since no more than two re-keys can happen simultaneously, this is enough.
122 struct GNUNET_CRYPTO_SymmetricSessionKey e_key_old2;
125 * Same as @c d_key_old, for the case described in @c e_key_old2.
127 struct GNUNET_CRYPTO_SymmetricSessionKey d_key_old2;
130 * Challenge to send and expect in the PONG.
135 * When the rekey started. One minute after this the new key will be used.
137 struct GNUNET_TIME_Absolute rekey_start_time;
140 * Task for delayed destruction of the Key eXchange context, to allow delayed
141 * messages with the old key to be decrypted successfully.
143 struct GNUNET_SCHEDULER_Task *finish_task;
147 * Encryption systems possible.
149 enum CadetTunnelEncryption
152 * Default Axolotl system.
157 * Fallback OTR-style encryption.
163 * Struct to old keys for skipped messages while advancing the Axolotl ratchet.
165 struct CadetTunnelSkippedKey
170 struct CadetTunnelSkippedKey *next;
175 struct CadetTunnelSkippedKey *prev;
178 * When was this key stored (for timeout).
180 struct GNUNET_TIME_Absolute timestamp;
185 struct GNUNET_CRYPTO_SymmetricSessionKey HK;
190 struct GNUNET_CRYPTO_SymmetricSessionKey MK;
195 * Axolotl data, according to https://github.com/trevp/axolotl/wiki .
197 struct CadetTunnelAxolotl
200 * A (double linked) list of stored message keys and associated header keys
201 * for "skipped" messages, i.e. messages that have not been
202 * received despite the reception of more recent messages, (head).
204 struct CadetTunnelSkippedKey *skipped_head;
207 * Skipped messages' keys DLL, tail.
209 struct CadetTunnelSkippedKey *skipped_tail;
212 * Elements in @a skipped_head <-> @a skipped_tail.
214 unsigned int skipped;
217 * 32-byte root key which gets updated by DH ratchet.
219 struct GNUNET_CRYPTO_SymmetricSessionKey RK;
222 * 32-byte header key (send).
224 struct GNUNET_CRYPTO_SymmetricSessionKey HKs;
227 * 32-byte header key (recv)
229 struct GNUNET_CRYPTO_SymmetricSessionKey HKr;
232 * 32-byte next header key (send).
234 struct GNUNET_CRYPTO_SymmetricSessionKey NHKs;
237 * 32-byte next header key (recv).
239 struct GNUNET_CRYPTO_SymmetricSessionKey NHKr;
242 * 32-byte chain keys (used for forward-secrecy updating, send).
244 struct GNUNET_CRYPTO_SymmetricSessionKey CKs;
247 * 32-byte chain keys (used for forward-secrecy updating, recv).
249 struct GNUNET_CRYPTO_SymmetricSessionKey CKr;
252 * ECDH for key exchange (A0 / B0).
254 struct GNUNET_CRYPTO_EcdhePrivateKey *kx_0;
257 * ECDH Ratchet key (send).
259 struct GNUNET_CRYPTO_EcdhePrivateKey *DHRs;
262 * ECDH Ratchet key (recv).
264 struct GNUNET_CRYPTO_EcdhePublicKey DHRr;
267 * Message number (reset to 0 with each new ratchet, next message to send).
272 * Message number (reset to 0 with each new ratchet, next message to recv).
277 * Previous message numbers (# of msgs sent under prev ratchet)
282 * True (#GNUNET_YES) if we have to send a new ratchet key in next msg.
287 * Number of messages recieved since our last ratchet advance.
288 * - If this counter = 0, we cannot send a new ratchet key in next msg.
289 * - If this counter > 0, we can (but don't yet have to) send a new key.
291 unsigned int ratchet_allowed;
294 * Number of messages recieved since our last ratchet advance.
295 * - If this counter = 0, we cannot send a new ratchet key in next msg.
296 * - If this counter > 0, we can (but don't yet have to) send a new key.
298 unsigned int ratchet_counter;
301 * When does this ratchet expire and a new one is triggered.
303 struct GNUNET_TIME_Absolute ratchet_expiration;
307 * Struct containing all information regarding a tunnel to a peer.
312 * Endpoint of the tunnel.
314 struct CadetPeer *peer;
317 * Type of encryption used in the tunnel.
319 enum CadetTunnelEncryption enc_type;
324 struct CadetTunnelAxolotl *ax;
327 * State of the tunnel connectivity.
329 enum CadetTunnelCState cstate;
332 * State of the tunnel encryption.
334 enum CadetTunnelEState estate;
337 * Key eXchange context.
339 struct CadetTunnelKXCtx *kx_ctx;
342 * Peer's ephemeral key, to recreate @c e_key and @c d_key when own ephemeral
345 struct GNUNET_CRYPTO_EcdhePublicKey peers_ephemeral_key;
348 * Encryption ("our") key. It is only "confirmed" if kx_ctx is NULL.
350 struct GNUNET_CRYPTO_SymmetricSessionKey e_key;
353 * Decryption ("their") key. It is only "confirmed" if kx_ctx is NULL.
355 struct GNUNET_CRYPTO_SymmetricSessionKey d_key;
358 * Task to start the rekey process.
360 struct GNUNET_SCHEDULER_Task * rekey_task;
363 * Paths that are actively used to reach the destination peer.
365 struct CadetTConnection *connection_head;
366 struct CadetTConnection *connection_tail;
369 * Next connection number.
374 * Channels inside this tunnel.
376 struct CadetTChannel *channel_head;
377 struct CadetTChannel *channel_tail;
380 * Channel ID for the next created channel.
382 CADET_ChannelNumber next_chid;
385 * Destroy flag: if true, destroy on last message.
387 struct GNUNET_SCHEDULER_Task * destroy_task;
390 * Queued messages, to transmit once tunnel gets connected.
392 struct CadetTunnelDelayed *tq_head;
393 struct CadetTunnelDelayed *tq_tail;
396 * Task to trim connections if too many are present.
398 struct GNUNET_SCHEDULER_Task * trim_connections_task;
401 * Ephemeral message in the queue (to avoid queueing more than one).
403 struct CadetConnectionQueue *ephm_h;
406 * Pong message in the queue.
408 struct CadetConnectionQueue *pong_h;
413 * Struct used to save messages in a non-ready tunnel to send once connected.
415 struct CadetTunnelDelayed
420 struct CadetTunnelDelayed *next;
421 struct CadetTunnelDelayed *prev;
426 struct CadetTunnel *t;
429 * Tunnel queue given to the channel to cancel request. Update on send_queued.
431 struct CadetTunnelQueue *tq;
436 /* struct GNUNET_MessageHeader *msg; */
441 * Handle for messages queued but not yet sent.
443 struct CadetTunnelQueue
446 * Connection queue handle, to cancel if necessary.
448 struct CadetConnectionQueue *cq;
451 * Handle in case message hasn't been given to a connection yet.
453 struct CadetTunnelDelayed *tqd;
456 * Continuation to call once sent.
461 * Closure for @c cont.
467 /******************************************************************************/
468 /******************************* GLOBALS ***********************************/
469 /******************************************************************************/
472 * Global handle to the statistics service.
474 extern struct GNUNET_STATISTICS_Handle *stats;
477 * Local peer own ID (memory efficient handle).
479 extern GNUNET_PEER_Id myid;
482 * Local peer own ID (full value).
484 extern struct GNUNET_PeerIdentity my_full_id;
488 * Don't try to recover tunnels if shutting down.
490 extern int shutting_down;
494 * Set of all tunnels, in order to trigger a new exchange on rekey.
495 * Indexed by peer's ID.
497 static struct GNUNET_CONTAINER_MultiPeerMap *tunnels;
500 * Default TTL for payload packets.
502 static unsigned long long default_ttl;
505 * Own Peer ID private key.
507 const static struct GNUNET_CRYPTO_EddsaPrivateKey *id_key;
510 /******************************** AXOLOTL ************************************/
513 * How many messages are needed to trigger a ratchet advance.
515 static unsigned long long ratchet_messages;
518 * How long until we trigger a ratched advance.
520 static struct GNUNET_TIME_Relative ratchet_time;
523 /******************************** OTR ***********************************/
526 * Own global OTR ephemeral private key.
528 static struct GNUNET_CRYPTO_EcdhePrivateKey *otr_ephemeral_key;
531 * Cached message used to perform a OTR key exchange.
533 static struct GNUNET_CADET_KX_Ephemeral otr_kx_msg;
536 * Task to generate a new OTR ephemeral key.
538 static struct GNUNET_SCHEDULER_Task *rekey_task;
543 static struct GNUNET_TIME_Relative rekey_period;
546 /******************************************************************************/
547 /******************************** STATIC ***********************************/
548 /******************************************************************************/
551 * Get string description for tunnel connectivity state.
553 * @param cs Tunnel state.
555 * @return String representation.
558 cstate2s (enum CadetTunnelCState cs)
564 case CADET_TUNNEL_NEW:
565 return "CADET_TUNNEL_NEW";
566 case CADET_TUNNEL_SEARCHING:
567 return "CADET_TUNNEL_SEARCHING";
568 case CADET_TUNNEL_WAITING:
569 return "CADET_TUNNEL_WAITING";
570 case CADET_TUNNEL_READY:
571 return "CADET_TUNNEL_READY";
572 case CADET_TUNNEL_SHUTDOWN:
573 return "CADET_TUNNEL_SHUTDOWN";
575 SPRINTF (buf, "%u (UNKNOWN STATE)", cs);
583 * Get string description for tunnel encryption state.
585 * @param es Tunnel state.
587 * @return String representation.
590 estate2s (enum CadetTunnelEState es)
596 case CADET_TUNNEL_KEY_UNINITIALIZED:
597 return "CADET_TUNNEL_KEY_UNINITIALIZED";
598 case CADET_TUNNEL_KEY_SENT:
599 return "CADET_TUNNEL_KEY_SENT";
600 case CADET_TUNNEL_KEY_PING:
601 return "CADET_TUNNEL_KEY_PING";
602 case CADET_TUNNEL_KEY_OK:
603 return "CADET_TUNNEL_KEY_OK";
604 case CADET_TUNNEL_KEY_REKEY:
605 return "CADET_TUNNEL_KEY_REKEY";
607 SPRINTF (buf, "%u (UNKNOWN STATE)", es);
615 * @brief Check if tunnel is ready to send traffic.
617 * Tunnel must be connected and with encryption correctly set up.
619 * @param t Tunnel to check.
621 * @return #GNUNET_YES if ready, #GNUNET_NO otherwise
624 is_ready (struct CadetTunnel *t)
628 ready = CADET_TUNNEL_READY == t->cstate
629 && (CADET_TUNNEL_KEY_OK == t->estate
630 || CADET_TUNNEL_KEY_REKEY == t->estate);
631 ready = ready || GCT_is_loopback (t);
637 * Check if a key is invalid (NULL pointer or all 0)
639 * @param key Key to check.
641 * @return #GNUNET_YES if key is null, #GNUNET_NO if exists and is not 0.
644 is_key_null (struct GNUNET_CRYPTO_SymmetricSessionKey *key)
646 struct GNUNET_CRYPTO_SymmetricSessionKey null_key;
651 memset (&null_key, 0, sizeof (null_key));
652 if (0 == memcmp (key, &null_key, sizeof (null_key)))
659 * Ephemeral key message purpose size.
661 * @return Size of the part of the ephemeral key message that must be signed.
664 ephemeral_purpose_size (void)
666 return sizeof (struct GNUNET_CRYPTO_EccSignaturePurpose) +
667 sizeof (struct GNUNET_TIME_AbsoluteNBO) +
668 sizeof (struct GNUNET_TIME_AbsoluteNBO) +
669 sizeof (struct GNUNET_CRYPTO_EcdhePublicKey) +
670 sizeof (struct GNUNET_PeerIdentity);
675 * Size of the encrypted part of a ping message.
677 * @return Size of the encrypted part of a ping message.
680 ping_encryption_size (void)
682 return sizeof (uint32_t);
687 * Get the channel's buffer. ONLY FOR NON-LOOPBACK CHANNELS!!
689 * @param tch Tunnel's channel handle.
691 * @return Amount of messages the channel can still buffer towards the client.
694 get_channel_buffer (const struct CadetTChannel *tch)
698 /* If channel is incoming, is terminal in the FWD direction and fwd is YES */
699 fwd = GCCH_is_terminal (tch->ch, GNUNET_YES);
701 return GCCH_get_buffer (tch->ch, fwd);
706 * Get the channel's allowance status.
708 * @param tch Tunnel's channel handle.
710 * @return #GNUNET_YES if we allowed the client to send data to us.
713 get_channel_allowed (const struct CadetTChannel *tch)
717 /* If channel is outgoing, is origin in the FWD direction and fwd is YES */
718 fwd = GCCH_is_origin (tch->ch, GNUNET_YES);
720 return GCCH_get_allowed (tch->ch, fwd);
725 * Get the connection's buffer.
727 * @param tc Tunnel's connection handle.
729 * @return Amount of messages the connection can still buffer.
732 get_connection_buffer (const struct CadetTConnection *tc)
736 /* If connection is outgoing, is origin in the FWD direction and fwd is YES */
737 fwd = GCC_is_origin (tc->c, GNUNET_YES);
739 return GCC_get_buffer (tc->c, fwd);
744 * Get the connection's allowance.
746 * @param tc Tunnel's connection handle.
748 * @return Amount of messages we have allowed the next peer to send us.
751 get_connection_allowed (const struct CadetTConnection *tc)
755 /* If connection is outgoing, is origin in the FWD direction and fwd is YES */
756 fwd = GCC_is_origin (tc->c, GNUNET_YES);
758 return GCC_get_allowed (tc->c, fwd);
763 * Check that a ephemeral key message s well formed and correctly signed.
765 * @param t Tunnel on which the message came.
766 * @param msg The ephemeral key message.
768 * @return #GNUNET_OK if message is fine, #GNUNET_SYSERR otherwise.
771 check_ephemeral (struct CadetTunnel *t,
772 const struct GNUNET_CADET_KX_Ephemeral *msg)
774 /* Check message size */
775 if (ntohs (msg->header.size) != sizeof (struct GNUNET_CADET_KX_Ephemeral))
776 return GNUNET_SYSERR;
778 /* Check signature size */
779 if (ntohl (msg->purpose.size) != ephemeral_purpose_size ())
780 return GNUNET_SYSERR;
783 if (0 != memcmp (&msg->origin_identity,
784 GCP_get_id (t->peer),
785 sizeof (struct GNUNET_PeerIdentity)))
786 return GNUNET_SYSERR;
788 /* Check signature */
790 GNUNET_CRYPTO_eddsa_verify (GNUNET_SIGNATURE_PURPOSE_CADET_KX,
793 &msg->origin_identity.public_key))
794 return GNUNET_SYSERR;
801 * Select the best key to use for encryption (send), based on KX status.
803 * Normally, return the current key. If there is a KX in progress and the old
804 * key is fresh enough, return the old key.
806 * @param t Tunnel to choose the key from.
808 * @return The optimal key to encrypt/hmac outgoing traffic.
810 static const struct GNUNET_CRYPTO_SymmetricSessionKey *
811 select_key (const struct CadetTunnel *t)
813 const struct GNUNET_CRYPTO_SymmetricSessionKey *key;
815 if (NULL != t->kx_ctx
816 && NULL == t->kx_ctx->finish_task)
818 struct GNUNET_TIME_Relative age;
820 age = GNUNET_TIME_absolute_get_duration (t->kx_ctx->rekey_start_time);
821 LOG (GNUNET_ERROR_TYPE_DEBUG,
822 " key exchange in progress, started %s ago\n",
823 GNUNET_STRINGS_relative_time_to_string (age, GNUNET_YES));
824 // FIXME make duration of old keys configurable
825 if (age.rel_value_us < GNUNET_TIME_UNIT_MINUTES.rel_value_us)
827 LOG (GNUNET_ERROR_TYPE_DEBUG, " using old key\n");
828 key = &t->kx_ctx->e_key_old;
832 LOG (GNUNET_ERROR_TYPE_DEBUG, " using new key (old key too old)\n");
838 LOG (GNUNET_ERROR_TYPE_DEBUG, " no KX: using current key\n");
846 * Create a new Axolotl ephemeral (ratchet) key.
851 new_ephemeral (struct CadetTunnel *t)
853 GNUNET_free_non_null (t->ax->DHRs);
854 t->ax->DHRs = GNUNET_CRYPTO_ecdhe_key_create();
861 * @param plaintext Content to HMAC.
862 * @param size Size of @c plaintext.
863 * @param iv Initialization vector for the message.
864 * @param key Key to use.
865 * @param hmac[out] Destination to store the HMAC.
868 t_hmac (const void *plaintext, size_t size,
869 uint32_t iv, const struct GNUNET_CRYPTO_SymmetricSessionKey *key,
870 struct GNUNET_CADET_Hash *hmac)
872 static const char ctx[] = "cadet authentication key";
873 struct GNUNET_CRYPTO_AuthKey auth_key;
874 struct GNUNET_HashCode hash;
876 #if DUMP_KEYS_TO_STDERR
877 LOG (GNUNET_ERROR_TYPE_INFO, " HMAC %u bytes with key %s\n", size,
878 GNUNET_h2s ((struct GNUNET_HashCode *) key));
880 GNUNET_CRYPTO_hmac_derive_key (&auth_key, key,
885 /* Two step: CADET_Hash is only 256 bits, HashCode is 512. */
886 GNUNET_CRYPTO_hmac (&auth_key, plaintext, size, &hash);
887 memcpy (hmac, &hash, sizeof (*hmac));
892 * Encrypt daforce_newest_keyta with the tunnel key.
894 * @param t Tunnel whose key to use.
895 * @param dst Destination for the encrypted data.
896 * @param src Source of the plaintext. Can overlap with @c dst.
897 * @param size Size of the plaintext.
898 * @param iv Initialization Vector to use.
899 * @param force_newest_key Force the use of the newest key, otherwise
900 * CADET will use the old key when allowed.
901 * This can happen in the case when a KX is going on
902 * and the old one hasn't expired.
905 t_encrypt (struct CadetTunnel *t, void *dst, const void *src,
906 size_t size, uint32_t iv, int force_newest_key)
908 struct GNUNET_CRYPTO_SymmetricInitializationVector siv;
909 const struct GNUNET_CRYPTO_SymmetricSessionKey *key;
912 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_encrypt start\n");
914 key = GNUNET_YES == force_newest_key ? &t->e_key : select_key (t);
915 #if DUMP_KEYS_TO_STDERR
916 LOG (GNUNET_ERROR_TYPE_INFO, " ENC with key %s\n",
917 GNUNET_h2s ((struct GNUNET_HashCode *) key));
919 GNUNET_CRYPTO_symmetric_derive_iv (&siv, key, &iv, sizeof (iv), NULL);
920 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_encrypt IV derived\n");
921 out_size = GNUNET_CRYPTO_symmetric_encrypt (src, size, key, &siv, dst);
922 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_encrypt end\n");
931 * @param key Key to use.
932 * @param hash[out] Resulting HMAC.
933 * @param source Source key material (data to HMAC).
934 * @param len Length of @a source.
937 t_ax_hmac_hash (struct GNUNET_CRYPTO_SymmetricSessionKey *key,
938 struct GNUNET_HashCode *hash,
939 void *source, unsigned int len)
941 static const char ctx[] = "axolotl HMAC-HASH";
942 struct GNUNET_CRYPTO_AuthKey auth_key;
944 GNUNET_CRYPTO_hmac_derive_key (&auth_key, key,
947 GNUNET_CRYPTO_hmac (&auth_key, source, len, hash);
952 * Derive a key from a HMAC-HASH.
954 * @param key Key to use for the HMAC.
955 * @param out Key to generate.
956 * @param source Source key material (data to HMAC).
957 * @param len Length of @a source.
960 t_hmac_derive_key (struct GNUNET_CRYPTO_SymmetricSessionKey *key,
961 struct GNUNET_CRYPTO_SymmetricSessionKey *out,
962 void *source, unsigned int len)
964 static const char ctx[] = "axolotl derive key";
965 struct GNUNET_HashCode h;
967 t_ax_hmac_hash (key, &h, source, len);
968 GNUNET_CRYPTO_kdf (out, sizeof (*out), ctx, sizeof (ctx),
969 &h, sizeof (h), NULL);
974 * Encrypt data with the axolotl tunnel key.
976 * @param t Tunnel whose key to use.
977 * @param dst Destination for the encrypted data.
978 * @param src Source of the plaintext. Can overlap with @c dst.
979 * @param size Size of the plaintext.
981 * @return Size of the encrypted data.
984 t_ax_encrypt (struct CadetTunnel *t, void *dst, const void *src, size_t size)
986 struct GNUNET_CRYPTO_SymmetricSessionKey MK;
987 struct GNUNET_CRYPTO_SymmetricInitializationVector iv;
988 struct CadetTunnelAxolotl *ax;
991 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_ax_encrypt start\n");
995 ax->ratchet_counter++;
996 if (GNUNET_YES == ax->ratchet_allowed
997 && (ratchet_messages <= ax->ratchet_counter
998 || 0 == GNUNET_TIME_absolute_get_remaining (ax->ratchet_expiration).rel_value_us))
1000 ax->ratchet_flag = GNUNET_YES;
1003 if (GNUNET_YES == ax->ratchet_flag)
1005 /* Advance ratchet */
1006 struct GNUNET_CRYPTO_SymmetricSessionKey keys[3];
1007 struct GNUNET_HashCode dh;
1008 struct GNUNET_HashCode hmac;
1009 static const char ctx[] = "axolotl ratchet";
1014 /* RK, NHKs, CKs = KDF( HMAC-HASH(RK, DH(DHRs, DHRr)) ) */
1015 GNUNET_CRYPTO_ecc_ecdh (ax->DHRs, &ax->DHRr, &dh);
1016 t_ax_hmac_hash (&ax->RK, &hmac, &dh, sizeof (dh));
1017 GNUNET_CRYPTO_kdf (keys, sizeof (keys), ctx, sizeof (ctx),
1018 &hmac, sizeof (hmac), NULL);
1025 ax->ratchet_flag = GNUNET_NO;
1026 ax->ratchet_allowed = GNUNET_NO;
1027 ax->ratchet_counter = 0;
1028 ax->ratchet_expiration =
1029 GNUNET_TIME_absolute_add (GNUNET_TIME_absolute_get(), ratchet_time);
1032 t_hmac_derive_key (&ax->CKs, &MK, "0", 1);
1033 GNUNET_CRYPTO_symmetric_derive_iv (&iv, &MK, NULL, 0, NULL);
1035 #if DUMP_KEYS_TO_STDERR
1036 LOG (GNUNET_ERROR_TYPE_INFO, " CKs: %s\n",
1037 GNUNET_h2s ((struct GNUNET_HashCode *) &ax->CKs));
1038 LOG (GNUNET_ERROR_TYPE_INFO, " AX_ENC with key %u: %s\n", ax->Ns,
1039 GNUNET_h2s ((struct GNUNET_HashCode *) &MK));
1042 out_size = GNUNET_CRYPTO_symmetric_encrypt (src, size, &MK, &iv, dst);
1044 t_hmac_derive_key (&ax->CKs, &ax->CKs, "1", 1);
1046 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_ax_encrypt end\n");
1053 * Decrypt data with the axolotl tunnel key.
1055 * @param t Tunnel whose key to use.
1056 * @param dst Destination for the decrypted data.
1057 * @param src Source of the ciphertext. Can overlap with @c dst.
1058 * @param size Size of the ciphertext.
1060 * @return Size of the decrypted data.
1063 t_ax_decrypt (struct CadetTunnel *t, void *dst, const void *src, size_t size)
1065 struct GNUNET_CRYPTO_SymmetricSessionKey MK;
1066 struct GNUNET_CRYPTO_SymmetricInitializationVector iv;
1067 struct CadetTunnelAxolotl *ax;
1070 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_ax_decrypt start\n");
1074 t_hmac_derive_key (&ax->CKr, &MK, "0", 1);
1075 GNUNET_CRYPTO_symmetric_derive_iv (&iv, &MK, NULL, 0, NULL);
1077 #if DUMP_KEYS_TO_STDERR
1078 LOG (GNUNET_ERROR_TYPE_INFO, " CKr: %s\n",
1079 GNUNET_h2s ((struct GNUNET_HashCode *) &ax->CKr));
1080 LOG (GNUNET_ERROR_TYPE_INFO, " AX_DEC with key %u: %s\n", ax->Nr,
1081 GNUNET_h2s ((struct GNUNET_HashCode *) &MK));
1084 GNUNET_assert (size >= sizeof (struct GNUNET_MessageHeader));
1085 out_size = GNUNET_CRYPTO_symmetric_decrypt (src, size, &MK, &iv, dst);
1086 GNUNET_assert (out_size == size);
1088 t_hmac_derive_key (&ax->CKr, &ax->CKr, "1", 1);
1090 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_ax_decrypt end\n");
1097 * Encrypt header with the axolotl header key.
1099 * @param t Tunnel whose key to use.
1100 * @param msg Message whose header to encrypt.
1103 t_h_encrypt (struct CadetTunnel *t, struct GNUNET_CADET_AX *msg)
1105 struct GNUNET_CRYPTO_SymmetricInitializationVector iv;
1106 struct CadetTunnelAxolotl *ax;
1109 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_h_encrypt start\n");
1112 GNUNET_CRYPTO_symmetric_derive_iv (&iv, &ax->HKs, NULL, 0, NULL);
1114 #if DUMP_KEYS_TO_STDERR
1115 LOG (GNUNET_ERROR_TYPE_INFO, " AX_ENC_H with key %s\n",
1116 GNUNET_h2s ((struct GNUNET_HashCode *) &ax->HKs));
1119 out_size = GNUNET_CRYPTO_symmetric_encrypt (&msg->Ns, AX_HEADER_SIZE,
1120 &ax->HKs, &iv, &msg->Ns);
1122 GNUNET_assert (AX_HEADER_SIZE == out_size);
1124 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_ax_encrypt end\n");
1129 * Decrypt header with the current axolotl header key.
1131 * @param t Tunnel whose current ax HK to use.
1132 * @param src Message whose header to decrypt.
1133 * @param dst Where to decrypt header to.
1136 t_h_decrypt (struct CadetTunnel *t, const struct GNUNET_CADET_AX *src,
1137 struct GNUNET_CADET_AX *dst)
1139 struct GNUNET_CRYPTO_SymmetricInitializationVector iv;
1140 struct CadetTunnelAxolotl *ax;
1143 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_h_decrypt start\n");
1146 GNUNET_CRYPTO_symmetric_derive_iv (&iv, &ax->HKr, NULL, 0, NULL);
1148 #if DUMP_KEYS_TO_STDERR
1149 LOG (GNUNET_ERROR_TYPE_INFO, " AX_DEC_H with key %s\n",
1150 GNUNET_h2s ((struct GNUNET_HashCode *) &ax->HKr));
1153 out_size = GNUNET_CRYPTO_symmetric_decrypt (&src->Ns, AX_HEADER_SIZE,
1154 &ax->HKr, &iv, &dst->Ns);
1156 GNUNET_assert (AX_HEADER_SIZE == out_size);
1158 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_ax_decrypt end\n");
1163 * Decrypt and verify data with the appropriate tunnel key.
1165 * @param key Key to use.
1166 * @param dst Destination for the plaintext.
1167 * @param src Source of the encrypted data. Can overlap with @c dst.
1168 * @param size Size of the encrypted data.
1169 * @param iv Initialization Vector to use.
1171 * @return Size of the decrypted data, -1 if an error was encountered.
1174 decrypt (const struct GNUNET_CRYPTO_SymmetricSessionKey *key,
1175 void *dst, const void *src, size_t size, uint32_t iv)
1177 struct GNUNET_CRYPTO_SymmetricInitializationVector siv;
1180 LOG (GNUNET_ERROR_TYPE_DEBUG, " decrypt start\n");
1181 LOG (GNUNET_ERROR_TYPE_DEBUG, " decrypt iv\n");
1182 GNUNET_CRYPTO_symmetric_derive_iv (&siv, key, &iv, sizeof (iv), NULL);
1183 LOG (GNUNET_ERROR_TYPE_DEBUG, " decrypt iv done\n");
1184 out_size = GNUNET_CRYPTO_symmetric_decrypt (src, size, key, &siv, dst);
1185 LOG (GNUNET_ERROR_TYPE_DEBUG, " decrypt end\n");
1192 * Decrypt and verify data with the most recent tunnel key.
1194 * @param t Tunnel whose key to use.
1195 * @param dst Destination for the plaintext.
1196 * @param src Source of the encrypted data. Can overlap with @c dst.
1197 * @param size Size of the encrypted data.
1198 * @param iv Initialization Vector to use.
1200 * @return Size of the decrypted data, -1 if an error was encountered.
1203 t_decrypt (struct CadetTunnel *t, void *dst, const void *src,
1204 size_t size, uint32_t iv)
1208 #if DUMP_KEYS_TO_STDERR
1209 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_decrypt with %s\n",
1210 GNUNET_h2s ((struct GNUNET_HashCode *) &t->d_key));
1212 if (CADET_TUNNEL_KEY_UNINITIALIZED == t->estate)
1214 GNUNET_STATISTICS_update (stats, "# non decryptable data", 1, GNUNET_NO);
1215 LOG (GNUNET_ERROR_TYPE_WARNING,
1216 "got data on %s without a valid key\n",
1218 GCT_debug (t, GNUNET_ERROR_TYPE_WARNING);
1222 out_size = decrypt (&t->d_key, dst, src, size, iv);
1229 * Decrypt and verify data with the appropriate tunnel key and verify that the
1230 * data has not been altered since it was sent by the remote peer.
1232 * @param t Tunnel whose key to use.
1233 * @param dst Destination for the plaintext.
1234 * @param src Source of the encrypted data. Can overlap with @c dst.
1235 * @param size Size of the encrypted data.
1236 * @param iv Initialization Vector to use.
1237 * @param msg_hmac HMAC of the message, cannot be NULL.
1239 * @return Size of the decrypted data, -1 if an error was encountered.
1242 t_decrypt_and_validate (struct CadetTunnel *t,
1243 void *dst, const void *src,
1244 size_t size, uint32_t iv,
1245 const struct GNUNET_CADET_Hash *msg_hmac)
1247 struct GNUNET_CRYPTO_SymmetricSessionKey *key;
1248 struct GNUNET_CADET_Hash hmac;
1251 /* Try primary (newest) key */
1253 decrypted_size = decrypt (key, dst, src, size, iv);
1254 t_hmac (src, size, iv, key, &hmac);
1255 if (0 == memcmp (msg_hmac, &hmac, sizeof (hmac)))
1256 return decrypted_size;
1258 /* If no key exchange is going on, we just failed. */
1259 if (NULL == t->kx_ctx)
1261 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
1262 "Failed checksum validation on tunnel %s with no KX\n",
1264 GNUNET_STATISTICS_update (stats, "# wrong HMAC no KX", 1, GNUNET_NO);
1268 /* Try secondary key, from previous KX period. */
1269 key = &t->kx_ctx->d_key_old;
1270 decrypted_size = decrypt (key, dst, src, size, iv);
1271 t_hmac (src, size, iv, key, &hmac);
1272 if (0 == memcmp (msg_hmac, &hmac, sizeof (hmac)))
1273 return decrypted_size;
1275 /* Hail Mary, try tertiary, key, in case of parallel re-keys. */
1276 key = &t->kx_ctx->d_key_old2;
1277 decrypted_size = decrypt (key, dst, src, size, iv);
1278 t_hmac (src, size, iv, key, &hmac);
1279 if (0 == memcmp (msg_hmac, &hmac, sizeof (hmac)))
1280 return decrypted_size;
1282 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
1283 "Failed checksum validation on tunnel %s with KX\n",
1285 GNUNET_STATISTICS_update (stats, "# wrong HMAC with KX", 1, GNUNET_NO);
1291 * Decrypt and verify data with the appropriate tunnel key and verify that the
1292 * data has not been altered since it was sent by the remote peer.
1294 * @param t Tunnel whose key to use.
1295 * @param dst Destination for the plaintext.
1296 * @param src Source of the message. Can overlap with @c dst.
1297 * @param size Size of the message.
1299 * @return Size of the decrypted data, -1 if an error was encountered.
1302 try_old_ax_keys (struct CadetTunnel *t, struct GNUNET_CADET_AX *dst,
1303 const struct GNUNET_CADET_AX *src, size_t size)
1305 struct CadetTunnelSkippedKey *key;
1306 struct GNUNET_CADET_Hash hmac;
1307 struct GNUNET_CRYPTO_SymmetricInitializationVector iv;
1312 for (key = t->ax->skipped_head; NULL != key; key = key->next)
1314 t_hmac (&src->Ns, AX_HEADER_SIZE, 0, &key->HK, &hmac);
1315 if (0 != memcmp (&hmac, &src->hmac, sizeof (hmac)))
1321 #if DUMP_KEYS_TO_STDERR
1322 LOG (GNUNET_ERROR_TYPE_INFO, " AX_DEC with skipped key %s\n",
1323 GNUNET_h2s ((struct GNUNET_HashCode *) &key->MK));
1326 GNUNET_assert (size > sizeof (struct GNUNET_CADET_AX));
1327 len = size - sizeof (struct GNUNET_CADET_AX);
1328 GNUNET_CRYPTO_symmetric_derive_iv (&iv, &key->MK, NULL, 0, NULL);
1329 res = GNUNET_CRYPTO_symmetric_decrypt (&src[1], len, &key->MK, &iv, &dst[1]);
1331 GNUNET_CONTAINER_DLL_remove (t->ax->skipped_head, t->ax->skipped_tail, key);
1340 * Delete a key from the list of skipped keys.
1342 * @param t Tunnel to delete from.
1343 * @param HKr Header Key to use.
1346 store_skipped_key (struct CadetTunnel *t,
1347 const struct GNUNET_CRYPTO_SymmetricSessionKey *HKr)
1349 struct CadetTunnelSkippedKey *key;
1351 key = GNUNET_new (struct CadetTunnelSkippedKey);
1352 key->timestamp = GNUNET_TIME_absolute_get ();
1353 t_hmac_derive_key (&t->ax->CKr, &key->MK, "0", 1);
1354 #if DUMP_KEYS_TO_STDERR
1355 LOG (GNUNET_ERROR_TYPE_INFO, " storing MK for Nr %u: %s\n",
1356 t->ax->Nr, GNUNET_h2s ((struct GNUNET_HashCode *) &key->MK));
1357 LOG (GNUNET_ERROR_TYPE_INFO, " for CKr: %s\n",
1358 GNUNET_h2s ((struct GNUNET_HashCode *) &t->ax->CKr));
1360 t_hmac_derive_key (&t->ax->CKr, &t->ax->CKr, "1", 1);
1361 GNUNET_CONTAINER_DLL_insert (t->ax->skipped_head, t->ax->skipped_tail, key);
1368 * Delete a key from the list of skipped keys.
1370 * @param t Tunnel to delete from.
1371 * @param key Key to delete.
1374 delete_skipped_key (struct CadetTunnel *t, struct CadetTunnelSkippedKey *key)
1376 GNUNET_CONTAINER_DLL_remove (t->ax->skipped_head, t->ax->skipped_tail, key);
1383 * Stage skipped AX keys and calculate the message key.
1385 * Stores each HK and MK for skipped messages.
1387 * @param t Tunnel where to stage the keys.
1388 * @param HKr Header key.
1389 * @param Np Received meesage number.
1392 store_ax_keys (struct CadetTunnel *t,
1393 const struct GNUNET_CRYPTO_SymmetricSessionKey *HKr,
1398 gap = Np - t->ax->Nr;
1399 if (MAX_KEY_GAP < gap || 0 > gap)
1401 /* Avoid DoS (forcing peer to do 2*33 chain HMAC operations) */
1402 /* TODO: start new key exchange on return */
1403 GNUNET_break_op (0);
1407 while (t->ax->Nr < Np)
1408 store_skipped_key (t, HKr);
1410 while (t->ax->skipped > MAX_SKIPPED_KEYS)
1411 delete_skipped_key (t, t->ax->skipped_tail);
1416 * Decrypt and verify data with the appropriate tunnel key and verify that the
1417 * data has not been altered since it was sent by the remote peer.
1419 * @param t Tunnel whose key to use.
1420 * @param dst Destination for the plaintext.
1421 * @param src Source of the message. Can overlap with @c dst.
1422 * @param size Size of the message.
1424 * @return Size of the decrypted data, -1 if an error was encountered.
1427 t_ax_decrypt_and_validate (struct CadetTunnel *t, void *dst,
1428 const struct GNUNET_CADET_AX *src, size_t size)
1430 struct CadetTunnelAxolotl *ax;
1431 struct GNUNET_CADET_Hash msg_hmac;
1432 struct GNUNET_HashCode hmac;
1433 struct GNUNET_CADET_AX *dstmsg;
1441 esize = size - sizeof (struct GNUNET_CADET_AX);
1446 /* Try current HK */
1447 t_hmac (&src->Ns, AX_HEADER_SIZE + esize, 0, &ax->HKr, &msg_hmac);
1448 if (0 != memcmp (&msg_hmac, &src->hmac, sizeof (msg_hmac)))
1450 static const char ctx[] = "axolotl ratchet";
1451 struct GNUNET_CRYPTO_SymmetricSessionKey keys[3]; /* RKp, NHKp, CKp */
1452 struct GNUNET_CRYPTO_SymmetricSessionKey HK;
1453 struct GNUNET_HashCode dh;
1454 struct GNUNET_CRYPTO_EcdhePublicKey *DHRp;
1457 t_hmac (&src->Ns, AX_HEADER_SIZE + esize, 0, &ax->NHKr, &msg_hmac);
1458 if (0 != memcmp (&msg_hmac, &src->hmac, sizeof (msg_hmac)))
1460 /* Try the skipped keys, if that fails, we're out of luck. */
1461 return try_old_ax_keys (t, dst, src, size);
1463 LOG (GNUNET_ERROR_TYPE_INFO, "next HK\n");
1467 t_h_decrypt (t, src, dstmsg);
1468 Np = ntohl (dstmsg->Ns);
1469 PNp = ntohl (dstmsg->PNs);
1470 DHRp = &dstmsg->DHRs;
1471 store_ax_keys (t, &HK, PNp);
1473 /* RKp, NHKp, CKp = KDF (HMAC-HASH (RK, DH (DHRp, DHRs))) */
1474 GNUNET_CRYPTO_ecc_ecdh (ax->DHRs, DHRp, &dh);
1475 t_ax_hmac_hash (&ax->RK, &hmac, &dh, sizeof (dh));
1476 GNUNET_CRYPTO_kdf (keys, sizeof (keys), ctx, sizeof (ctx),
1477 &hmac, sizeof (hmac), NULL);
1479 /* Commit "purported" keys */
1485 ax->ratchet_allowed = GNUNET_YES;
1489 LOG (GNUNET_ERROR_TYPE_DEBUG, "current HK\n");
1490 t_h_decrypt (t, src, dstmsg);
1491 Np = ntohl (dstmsg->Ns);
1492 PNp = ntohl (dstmsg->PNs);
1496 store_ax_keys (t, &ax->HKr, Np);
1500 osize = t_ax_decrypt (t, dst, &src[1], esize);
1503 GNUNET_break_op (0);
1512 * Create key material by doing ECDH on the local and remote ephemeral keys.
1514 * @param key_material Where to store the key material.
1515 * @param ephemeral Peer's public ephemeral key.
1517 * @return GNUNET_OK if it went fine, GNUNET_SYSERR otherwise.
1520 derive_otr_key_material (struct GNUNET_HashCode *key_material,
1521 const struct GNUNET_CRYPTO_EcdhePublicKey *ephemeral)
1524 GNUNET_CRYPTO_ecc_ecdh (otr_ephemeral_key, ephemeral, key_material))
1527 return GNUNET_SYSERR;
1534 * Create a symmetic key from the identities of both ends and the key material
1537 * @param key Destination for the generated key.
1538 * @param sender ID of the peer that will encrypt with @c key.
1539 * @param receiver ID of the peer that will decrypt with @c key.
1540 * @param key_material Hash created with ECDH with the ephemeral keys.
1543 derive_symmertic (struct GNUNET_CRYPTO_SymmetricSessionKey *key,
1544 const struct GNUNET_PeerIdentity *sender,
1545 const struct GNUNET_PeerIdentity *receiver,
1546 const struct GNUNET_HashCode *key_material)
1548 const char salt[] = "CADET kx salt";
1550 GNUNET_CRYPTO_kdf (key, sizeof (struct GNUNET_CRYPTO_SymmetricSessionKey),
1551 salt, sizeof (salt),
1552 key_material, sizeof (struct GNUNET_HashCode),
1553 sender, sizeof (struct GNUNET_PeerIdentity),
1554 receiver, sizeof (struct GNUNET_PeerIdentity),
1560 * Derive the tunnel's keys using our own and the peer's ephemeral keys.
1562 * @param t Tunnel for which to create the keys.
1564 * @return GNUNET_OK if successful, GNUNET_SYSERR otherwise.
1567 create_otr_keys (struct CadetTunnel *t)
1569 struct GNUNET_HashCode km;
1571 if (GNUNET_OK != derive_otr_key_material (&km, &t->peers_ephemeral_key))
1572 return GNUNET_SYSERR;
1573 derive_symmertic (&t->e_key, &my_full_id, GCP_get_id (t->peer), &km);
1574 derive_symmertic (&t->d_key, GCP_get_id (t->peer), &my_full_id, &km);
1575 #if DUMP_KEYS_TO_STDERR
1576 LOG (GNUNET_ERROR_TYPE_INFO, "ME: %s\n",
1577 GNUNET_h2s ((struct GNUNET_HashCode *) &otr_kx_msg.ephemeral_key));
1578 LOG (GNUNET_ERROR_TYPE_INFO, "PE: %s\n",
1579 GNUNET_h2s ((struct GNUNET_HashCode *) &t->peers_ephemeral_key));
1580 LOG (GNUNET_ERROR_TYPE_INFO, "KM: %s\n", GNUNET_h2s (&km));
1581 LOG (GNUNET_ERROR_TYPE_INFO, "EK: %s\n",
1582 GNUNET_h2s ((struct GNUNET_HashCode *) &t->e_key));
1583 LOG (GNUNET_ERROR_TYPE_INFO, "DK: %s\n",
1584 GNUNET_h2s ((struct GNUNET_HashCode *) &t->d_key));
1591 * Create a new Key eXchange context for the tunnel.
1593 * If the old keys were verified, keep them for old traffic. Create a new KX
1594 * timestamp and a new nonce.
1596 * @param t Tunnel for which to create the KX ctx.
1598 * @return GNUNET_OK if successful, GNUNET_SYSERR otherwise.
1601 create_kx_ctx (struct CadetTunnel *t)
1603 LOG (GNUNET_ERROR_TYPE_INFO, " new kx ctx for %s\n", GCT_2s (t));
1605 if (NULL != t->kx_ctx)
1607 if (NULL != t->kx_ctx->finish_task)
1609 LOG (GNUNET_ERROR_TYPE_INFO, " resetting exisiting finish task\n");
1610 GNUNET_SCHEDULER_cancel (t->kx_ctx->finish_task);
1611 t->kx_ctx->finish_task = NULL;
1616 t->kx_ctx = GNUNET_new (struct CadetTunnelKXCtx);
1617 t->kx_ctx->challenge = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE,
1621 if (CADET_TUNNEL_KEY_OK == t->estate)
1623 LOG (GNUNET_ERROR_TYPE_INFO, " backing up keys\n");
1624 t->kx_ctx->d_key_old = t->d_key;
1625 t->kx_ctx->e_key_old = t->e_key;
1628 LOG (GNUNET_ERROR_TYPE_INFO, " old keys not valid, not saving\n");
1629 t->kx_ctx->rekey_start_time = GNUNET_TIME_absolute_get ();
1630 return create_otr_keys (t);
1635 * @brief Finish the Key eXchange and destroy the old keys.
1637 * @param cls Closure (Tunnel for which to finish the KX).
1638 * @param tc Task context.
1641 finish_kx (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
1643 struct CadetTunnel *t = cls;
1645 LOG (GNUNET_ERROR_TYPE_INFO, "finish KX for %s\n", GCT_2s (t));
1647 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
1649 LOG (GNUNET_ERROR_TYPE_INFO, " shutdown\n");
1653 GNUNET_free (t->kx_ctx);
1659 * Destroy a Key eXchange context for the tunnel. This function only schedules
1660 * the destruction, the freeing of the memory (and clearing of old key material)
1661 * happens after a delay!
1663 * @param t Tunnel whose KX ctx to destroy.
1666 destroy_kx_ctx (struct CadetTunnel *t)
1668 struct GNUNET_TIME_Relative delay;
1670 if (NULL == t->kx_ctx || NULL != t->kx_ctx->finish_task)
1673 if (is_key_null (&t->kx_ctx->e_key_old))
1675 t->kx_ctx->finish_task = GNUNET_SCHEDULER_add_now (finish_kx, t);
1679 delay = GNUNET_TIME_relative_divide (rekey_period, 4);
1680 delay = GNUNET_TIME_relative_min (delay, GNUNET_TIME_UNIT_MINUTES);
1682 t->kx_ctx->finish_task = GNUNET_SCHEDULER_add_delayed (delay, finish_kx, t);
1688 * Pick a connection on which send the next data message.
1690 * @param t Tunnel on which to send the message.
1692 * @return The connection on which to send the next message.
1694 static struct CadetConnection *
1695 tunnel_get_connection (struct CadetTunnel *t)
1697 struct CadetTConnection *iter;
1698 struct CadetConnection *best;
1700 unsigned int lowest_q;
1702 LOG (GNUNET_ERROR_TYPE_DEBUG, "tunnel_get_connection %s\n", GCT_2s (t));
1704 lowest_q = UINT_MAX;
1705 for (iter = t->connection_head; NULL != iter; iter = iter->next)
1707 LOG (GNUNET_ERROR_TYPE_DEBUG, " connection %s: %u\n",
1708 GCC_2s (iter->c), GCC_get_state (iter->c));
1709 if (CADET_CONNECTION_READY == GCC_get_state (iter->c))
1711 qn = GCC_get_qn (iter->c, GCC_is_origin (iter->c, GNUNET_YES));
1712 LOG (GNUNET_ERROR_TYPE_DEBUG, " q_n %u, \n", qn);
1720 LOG (GNUNET_ERROR_TYPE_DEBUG, " selected: connection %s\n", GCC_2s (best));
1726 * Callback called when a queued message is sent.
1728 * Calculates the average time and connection packet tracking.
1730 * @param cls Closure (TunnelQueue handle).
1731 * @param c Connection this message was on.
1732 * @param q Connection queue handle (unused).
1733 * @param type Type of message sent.
1734 * @param fwd Was this a FWD going message?
1735 * @param size Size of the message.
1738 tun_message_sent (void *cls,
1739 struct CadetConnection *c,
1740 struct CadetConnectionQueue *q,
1741 uint16_t type, int fwd, size_t size)
1743 struct CadetTunnelQueue *qt = cls;
1744 struct CadetTunnel *t;
1746 LOG (GNUNET_ERROR_TYPE_DEBUG, "tun_message_sent\n");
1748 GNUNET_assert (NULL != qt->cont);
1749 t = NULL == c ? NULL : GCC_get_tunnel (c);
1750 qt->cont (qt->cont_cls, t, qt, type, size);
1756 count_queued_data (const struct CadetTunnel *t)
1758 struct CadetTunnelDelayed *iter;
1761 for (count = 0, iter = t->tq_head; iter != NULL; iter = iter->next)
1768 * Delete a queued message: either was sent or the channel was destroyed
1769 * before the tunnel's key exchange had a chance to finish.
1771 * @param tqd Delayed queue handle.
1774 unqueue_data (struct CadetTunnelDelayed *tqd)
1776 GNUNET_CONTAINER_DLL_remove (tqd->t->tq_head, tqd->t->tq_tail, tqd);
1782 * Cache a message to be sent once tunnel is online.
1784 * @param t Tunnel to hold the message.
1785 * @param msg Message itself (copy will be made).
1787 static struct CadetTunnelDelayed *
1788 queue_data (struct CadetTunnel *t, const struct GNUNET_MessageHeader *msg)
1790 struct CadetTunnelDelayed *tqd;
1791 uint16_t size = ntohs (msg->size);
1793 LOG (GNUNET_ERROR_TYPE_DEBUG, "queue data on Tunnel %s\n", GCT_2s (t));
1795 GNUNET_assert (GNUNET_NO == is_ready (t));
1797 tqd = GNUNET_malloc (sizeof (struct CadetTunnelDelayed) + size);
1800 memcpy (&tqd[1], msg, size);
1801 GNUNET_CONTAINER_DLL_insert_tail (t->tq_head, t->tq_tail, tqd);
1807 * Sends an already built message on a tunnel, encrypting it and
1808 * choosing the best connection.
1810 * @param message Message to send. Function modifies it.
1811 * @param t Tunnel on which this message is transmitted.
1812 * @param c Connection to use (autoselect if NULL).
1813 * @param force Force the tunnel to take the message (buffer overfill).
1814 * @param cont Continuation to call once message is really sent.
1815 * @param cont_cls Closure for @c cont.
1816 * @param existing_q In case this a transmission of previously queued data,
1817 * this should be TunnelQueue given to the client.
1820 * @return Handle to cancel message.
1821 * NULL if @c cont is NULL or an error happens and message is dropped.
1823 static struct CadetTunnelQueue *
1824 send_prebuilt_message (const struct GNUNET_MessageHeader *message,
1825 struct CadetTunnel *t, struct CadetConnection *c,
1826 int force, GCT_sent cont, void *cont_cls,
1827 struct CadetTunnelQueue *existing_q)
1829 struct GNUNET_MessageHeader *msg;
1830 struct GNUNET_CADET_Encrypted *otr_msg;
1831 struct GNUNET_CADET_AX *ax_msg;
1832 struct CadetTunnelQueue *tq;
1833 size_t size = ntohs (message->size);
1834 const uint16_t max_overhead = sizeof (struct GNUNET_CADET_Encrypted)
1835 + sizeof (struct GNUNET_CADET_AX);
1836 char cbuf[max_overhead + size];
1843 LOG (GNUNET_ERROR_TYPE_DEBUG, "GMT Send on Tunnel %s\n", GCT_2s (t));
1845 if (GNUNET_NO == is_ready (t))
1847 struct CadetTunnelDelayed *tqd;
1848 /* A non null existing_q indicates sending of queued data.
1849 * Should only happen after tunnel becomes ready.
1851 GNUNET_assert (NULL == existing_q);
1852 tqd = queue_data (t, message);
1855 tq = GNUNET_new (struct CadetTunnelQueue);
1859 tq->cont_cls = cont_cls;
1863 GNUNET_assert (GNUNET_NO == GCT_is_loopback (t));
1865 if (CADET_Axolotl == t->enc_type)
1867 ax_msg = (struct GNUNET_CADET_AX *) cbuf;
1868 msg = &ax_msg->header;
1869 msg->size = htons (sizeof (struct GNUNET_CADET_AX) + size);
1870 msg->type = htons (GNUNET_MESSAGE_TYPE_CADET_AX);
1871 ax_msg->reserved = 0;
1872 esize = t_ax_encrypt (t, &ax_msg[1], message, size);
1873 ax_msg->Ns = htonl (t->ax->Ns++);
1874 ax_msg->PNs = htonl (t->ax->PNs);
1875 GNUNET_CRYPTO_ecdhe_key_get_public (t->ax->DHRs, &ax_msg->DHRs);
1876 t_h_encrypt (t, ax_msg);
1877 t_hmac (&ax_msg->Ns, AX_HEADER_SIZE + esize, 0, &t->ax->HKs, &ax_msg->hmac);
1881 otr_msg = (struct GNUNET_CADET_Encrypted *) cbuf;
1882 msg = &otr_msg->header;
1883 iv = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX);
1885 esize = t_encrypt (t, &otr_msg[1], message, size, iv, GNUNET_NO);
1886 t_hmac (&otr_msg[1], size, iv, select_key (t), &otr_msg->hmac);
1887 msg->size = htons (sizeof (struct GNUNET_CADET_Encrypted) + size);
1888 msg->type = htons (GNUNET_MESSAGE_TYPE_CADET_ENCRYPTED);
1889 otr_msg->ttl = htonl (default_ttl);
1891 GNUNET_assert (esize == size);
1894 c = tunnel_get_connection (t);
1897 /* Why is tunnel 'ready'? Should have been queued! */
1898 if (NULL != t->destroy_task)
1901 GCT_debug (t, GNUNET_ERROR_TYPE_WARNING);
1903 return NULL; /* Drop... */
1907 type = ntohs (message->type);
1910 case GNUNET_MESSAGE_TYPE_CADET_DATA:
1911 case GNUNET_MESSAGE_TYPE_CADET_DATA_ACK:
1912 if (GNUNET_MESSAGE_TYPE_CADET_DATA == type)
1913 mid = ntohl (((struct GNUNET_CADET_Data *) message)->mid);
1915 mid = ntohl (((struct GNUNET_CADET_DataACK *) message)->mid);
1917 case GNUNET_MESSAGE_TYPE_CADET_KEEPALIVE:
1918 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_CREATE:
1919 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_DESTROY:
1920 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_ACK:
1921 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_NACK:
1925 LOG (GNUNET_ERROR_TYPE_ERROR, "type %s not valid\n", GC_m2s (type));
1927 LOG (GNUNET_ERROR_TYPE_DEBUG, "type %s\n", GC_m2s (type));
1929 fwd = GCC_is_origin (c, GNUNET_YES);
1933 GNUNET_break (NULL == GCC_send_prebuilt_message (msg, type,
1934 mid, c, fwd, force, NULL, NULL));
1937 if (NULL == existing_q)
1939 tq = GNUNET_new (struct CadetTunnelQueue); /* FIXME valgrind: leak*/
1946 tq->cq = GCC_send_prebuilt_message (msg, type, mid, c, fwd, force,
1947 &tun_message_sent, tq);
1948 GNUNET_assert (NULL != tq->cq);
1950 tq->cont_cls = cont_cls;
1957 * Send all cached messages that we can, tunnel is online.
1959 * @param t Tunnel that holds the messages. Cannot be loopback.
1962 send_queued_data (struct CadetTunnel *t)
1964 struct CadetTunnelDelayed *tqd;
1965 struct CadetTunnelDelayed *next;
1968 LOG (GNUNET_ERROR_TYPE_INFO, "Send queued data, tunnel %s\n", GCT_2s (t));
1970 if (GCT_is_loopback (t))
1976 if (GNUNET_NO == is_ready (t))
1978 LOG (GNUNET_ERROR_TYPE_DEBUG, " not ready yet: %s/%s\n",
1979 estate2s (t->estate), cstate2s (t->cstate));
1983 room = GCT_get_connections_buffer (t);
1984 LOG (GNUNET_ERROR_TYPE_DEBUG, " buffer space: %u\n", room);
1985 LOG (GNUNET_ERROR_TYPE_DEBUG, " tq head: %p\n", t->tq_head);
1986 for (tqd = t->tq_head; NULL != tqd && room > 0; tqd = next)
1988 LOG (GNUNET_ERROR_TYPE_DEBUG, " sending queued data\n");
1991 send_prebuilt_message ((struct GNUNET_MessageHeader *) &tqd[1],
1992 tqd->t, NULL, GNUNET_YES,
1993 NULL != tqd->tq ? tqd->tq->cont : NULL,
1994 NULL != tqd->tq ? tqd->tq->cont_cls : NULL,
1998 LOG (GNUNET_ERROR_TYPE_DEBUG, "GCT_send_queued_data end\n", GCP_2s (t->peer));
2003 * @brief Resend the AX KX until we complete the handshake.
2005 * @param cls Closure (tunnel).
2006 * @param tc Task context.
2009 ax_kx_resend (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
2011 struct CadetTunnel *t = cls;
2013 t->rekey_task = NULL;
2015 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
2018 if (CADET_TUNNEL_KEY_OK == t->estate)
2021 GCT_send_ax_kx (t, GNUNET_YES);
2026 * Callback called when a queued message is sent.
2028 * @param cls Closure.
2029 * @param c Connection this message was on.
2030 * @param type Type of message sent.
2031 * @param fwd Was this a FWD going message?
2032 * @param size Size of the message.
2035 ephm_sent (void *cls,
2036 struct CadetConnection *c,
2037 struct CadetConnectionQueue *q,
2038 uint16_t type, int fwd, size_t size)
2040 struct CadetTunnel *t = cls;
2041 LOG (GNUNET_ERROR_TYPE_DEBUG, "ephemeral sent %s\n", GC_m2s (type));
2045 if (CADET_TUNNEL_KEY_OK == t->estate)
2048 if (CADET_Axolotl == t->enc_type && CADET_TUNNEL_KEY_OK != t->estate)
2050 if (NULL != t->rekey_task)
2053 GNUNET_SCHEDULER_cancel (t->rekey_task);
2055 t->rekey_task = GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_SECONDS,
2062 * Callback called when a queued message is sent.
2064 * @param cls Closure.
2065 * @param c Connection this message was on.
2066 * @param type Type of message sent.
2067 * @param fwd Was this a FWD going message?
2068 * @param size Size of the message.
2071 pong_sent (void *cls,
2072 struct CadetConnection *c,
2073 struct CadetConnectionQueue *q,
2074 uint16_t type, int fwd, size_t size)
2076 struct CadetTunnel *t = cls;
2077 LOG (GNUNET_ERROR_TYPE_DEBUG, "pong_sent %s\n", GC_m2s (type));
2084 * Sends key exchange message on a tunnel, choosing the best connection.
2085 * Should not be called on loopback tunnels.
2087 * @param t Tunnel on which this message is transmitted.
2088 * @param message Message to send. Function modifies it.
2090 * @return Handle to the message in the connection queue.
2092 static struct CadetConnectionQueue *
2093 send_kx (struct CadetTunnel *t,
2094 const struct GNUNET_MessageHeader *message)
2096 struct CadetConnection *c;
2097 struct GNUNET_CADET_KX *msg;
2098 size_t size = ntohs (message->size);
2099 char cbuf[sizeof (struct GNUNET_CADET_KX) + size];
2104 LOG (GNUNET_ERROR_TYPE_DEBUG, "GMT KX on Tunnel %s\n", GCT_2s (t));
2106 /* Avoid loopback. */
2107 if (GCT_is_loopback (t))
2112 type = ntohs (message->type);
2114 /* Even if tunnel is "being destroyed", send anyway.
2115 * Could be a response to a rekey initiated by remote peer,
2116 * who is trying to create a new channel!
2119 /* Must have a connection, or be looking for one. */
2120 if (NULL == t->connection_head)
2122 LOG (GNUNET_ERROR_TYPE_DEBUG, "%s with no connection\n", GC_m2s (type));
2123 if (CADET_TUNNEL_SEARCHING != t->cstate)
2126 GCT_debug (t, GNUNET_ERROR_TYPE_ERROR);
2127 GCP_debug (t->peer, GNUNET_ERROR_TYPE_ERROR);
2132 msg = (struct GNUNET_CADET_KX *) cbuf;
2133 msg->header.type = htons (GNUNET_MESSAGE_TYPE_CADET_KX);
2134 msg->header.size = htons (sizeof (struct GNUNET_CADET_KX) + size);
2135 c = tunnel_get_connection (t);
2138 if (NULL == t->destroy_task && CADET_TUNNEL_READY == t->cstate)
2141 GCT_debug (t, GNUNET_ERROR_TYPE_ERROR);
2147 case GNUNET_MESSAGE_TYPE_CADET_KX_EPHEMERAL:
2148 case GNUNET_MESSAGE_TYPE_CADET_AX_KX:
2149 GNUNET_assert (NULL == t->ephm_h);
2152 case GNUNET_MESSAGE_TYPE_CADET_KX_PONG:
2153 GNUNET_assert (NULL == t->pong_h);
2158 LOG (GNUNET_ERROR_TYPE_DEBUG, "unkown type %s\n", GC_m2s (type));
2161 memcpy (&msg[1], message, size);
2163 fwd = GCC_is_origin (c, GNUNET_YES);
2165 return GCC_send_prebuilt_message (&msg->header, type, 0, c,
2172 * Send the ephemeral key on a tunnel.
2174 * @param t Tunnel on which to send the key.
2177 send_ephemeral (struct CadetTunnel *t)
2179 LOG (GNUNET_ERROR_TYPE_INFO, "===> EPHM for %s\n", GCT_2s (t));
2180 if (NULL != t->ephm_h)
2182 LOG (GNUNET_ERROR_TYPE_INFO, " already queued\n");
2186 otr_kx_msg.sender_status = htonl (t->estate);
2187 otr_kx_msg.iv = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX);
2188 otr_kx_msg.nonce = t->kx_ctx->challenge;
2189 LOG (GNUNET_ERROR_TYPE_DEBUG, " send nonce c %u\n", otr_kx_msg.nonce);
2190 t_encrypt (t, &otr_kx_msg.nonce, &otr_kx_msg.nonce,
2191 ping_encryption_size(), otr_kx_msg.iv, GNUNET_YES);
2192 LOG (GNUNET_ERROR_TYPE_DEBUG, " send nonce e %u\n", otr_kx_msg.nonce);
2193 t->ephm_h = send_kx (t, &otr_kx_msg.header);
2198 * Send a pong message on a tunnel.
2200 * @param t Tunnel on which to send the pong.
2201 * @param challenge Value sent in the ping that we have to send back.
2204 send_pong (struct CadetTunnel *t, uint32_t challenge)
2206 struct GNUNET_CADET_KX_Pong msg;
2208 LOG (GNUNET_ERROR_TYPE_INFO, "===> PONG for %s\n", GCT_2s (t));
2209 if (NULL != t->pong_h)
2211 LOG (GNUNET_ERROR_TYPE_INFO, " already queued\n");
2214 msg.header.size = htons (sizeof (msg));
2215 msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_KX_PONG);
2216 msg.iv = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX);
2217 msg.nonce = challenge;
2218 LOG (GNUNET_ERROR_TYPE_DEBUG, " sending %u\n", msg.nonce);
2219 t_encrypt (t, &msg.nonce, &msg.nonce,
2220 sizeof (msg.nonce), msg.iv, GNUNET_YES);
2221 LOG (GNUNET_ERROR_TYPE_DEBUG, " e sending %u\n", msg.nonce);
2223 t->pong_h = send_kx (t, &msg.header);
2228 * Initiate a rekey with the remote peer.
2230 * @param cls Closure (tunnel).
2231 * @param tc TaskContext.
2234 rekey_tunnel (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
2236 struct CadetTunnel *t = cls;
2238 t->rekey_task = NULL;
2240 LOG (GNUNET_ERROR_TYPE_INFO, "Re-key Tunnel %s\n", GCT_2s (t));
2241 if (NULL != tc && 0 != (GNUNET_SCHEDULER_REASON_SHUTDOWN & tc->reason))
2244 GNUNET_assert (NULL != t->kx_ctx);
2245 struct GNUNET_TIME_Relative duration;
2247 duration = GNUNET_TIME_absolute_get_duration (t->kx_ctx->rekey_start_time);
2248 LOG (GNUNET_ERROR_TYPE_DEBUG, " kx started %s ago\n",
2249 GNUNET_STRINGS_relative_time_to_string (duration, GNUNET_YES));
2251 // FIXME make duration of old keys configurable
2252 if (duration.rel_value_us >= GNUNET_TIME_UNIT_MINUTES.rel_value_us)
2254 LOG (GNUNET_ERROR_TYPE_DEBUG, " deleting old keys\n");
2255 memset (&t->kx_ctx->d_key_old, 0, sizeof (t->kx_ctx->d_key_old));
2256 memset (&t->kx_ctx->e_key_old, 0, sizeof (t->kx_ctx->e_key_old));
2263 case CADET_TUNNEL_KEY_UNINITIALIZED:
2264 GCT_change_estate (t, CADET_TUNNEL_KEY_SENT);
2267 case CADET_TUNNEL_KEY_SENT:
2270 case CADET_TUNNEL_KEY_OK:
2272 * - state should have changed during rekey_iterator
2273 * - task should have been canceled at pong_handle
2276 GCT_change_estate (t, CADET_TUNNEL_KEY_REKEY);
2279 case CADET_TUNNEL_KEY_PING:
2280 case CADET_TUNNEL_KEY_REKEY:
2284 LOG (GNUNET_ERROR_TYPE_DEBUG, "Unexpected state %u\n", t->estate);
2287 // FIXME exponential backoff
2288 struct GNUNET_TIME_Relative delay;
2290 delay = GNUNET_TIME_relative_divide (rekey_period, 16);
2291 delay = GNUNET_TIME_relative_min (delay, REKEY_WAIT);
2292 LOG (GNUNET_ERROR_TYPE_DEBUG, " next call in %s\n",
2293 GNUNET_STRINGS_relative_time_to_string (delay, GNUNET_YES));
2294 t->rekey_task = GNUNET_SCHEDULER_add_delayed (delay, &rekey_tunnel, t);
2299 * Our ephemeral key has changed, create new session key on all tunnels.
2301 * Each tunnel will start the Key Exchange with a random delay between
2302 * 0 and number_of_tunnels*100 milliseconds, so there are 10 key exchanges
2303 * per second, on average.
2305 * @param cls Closure (size of the hashmap).
2306 * @param key Current public key.
2307 * @param value Value in the hash map (tunnel).
2309 * @return #GNUNET_YES, so we should continue to iterate,
2312 rekey_iterator (void *cls,
2313 const struct GNUNET_PeerIdentity *key,
2316 struct CadetTunnel *t = value;
2317 struct GNUNET_TIME_Relative delay;
2318 long n = (long) cls;
2321 if (NULL != t->rekey_task)
2324 if (GNUNET_YES == GCT_is_loopback (t))
2327 if (CADET_OTR != t->enc_type)
2330 r = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK, (uint32_t) n * 100);
2331 delay = GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MILLISECONDS, r);
2332 t->rekey_task = GNUNET_SCHEDULER_add_delayed (delay, &rekey_tunnel, t);
2333 if (GNUNET_OK == create_kx_ctx (t))
2334 GCT_change_estate (t, CADET_TUNNEL_KEY_REKEY);
2346 * Create a new ephemeral key and key message, schedule next rekeying.
2348 * @param cls Closure (unused).
2349 * @param tc TaskContext.
2352 global_otr_rekey (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
2354 struct GNUNET_TIME_Absolute time;
2359 if (0 != (GNUNET_SCHEDULER_REASON_SHUTDOWN & tc->reason))
2362 GNUNET_free_non_null (otr_ephemeral_key);
2363 otr_ephemeral_key = GNUNET_CRYPTO_ecdhe_key_create ();
2365 time = GNUNET_TIME_absolute_get ();
2366 otr_kx_msg.creation_time = GNUNET_TIME_absolute_hton (time);
2367 time = GNUNET_TIME_absolute_add (time, rekey_period);
2368 time = GNUNET_TIME_absolute_add (time, GNUNET_TIME_UNIT_MINUTES);
2369 otr_kx_msg.expiration_time = GNUNET_TIME_absolute_hton (time);
2370 GNUNET_CRYPTO_ecdhe_key_get_public (otr_ephemeral_key, &otr_kx_msg.ephemeral_key);
2371 LOG (GNUNET_ERROR_TYPE_INFO, "GLOBAL OTR RE-KEY, NEW EPHM: %s\n",
2372 GNUNET_h2s ((struct GNUNET_HashCode *) &otr_kx_msg.ephemeral_key));
2374 GNUNET_assert (GNUNET_OK ==
2375 GNUNET_CRYPTO_eddsa_sign (id_key,
2376 &otr_kx_msg.purpose,
2377 &otr_kx_msg.signature));
2379 n = (long) GNUNET_CONTAINER_multipeermap_size (tunnels);
2380 GNUNET_CONTAINER_multipeermap_iterate (tunnels, &rekey_iterator, (void *) n);
2382 rekey_task = GNUNET_SCHEDULER_add_delayed (rekey_period,
2383 &global_otr_rekey, NULL);
2388 * Called only on shutdown, destroy every tunnel.
2390 * @param cls Closure (unused).
2391 * @param key Current public key.
2392 * @param value Value in the hash map (tunnel).
2394 * @return #GNUNET_YES, so we should continue to iterate,
2397 destroy_iterator (void *cls,
2398 const struct GNUNET_PeerIdentity *key,
2401 struct CadetTunnel *t = value;
2403 LOG (GNUNET_ERROR_TYPE_DEBUG, "GCT_shutdown destroying tunnel at %p\n", t);
2410 * Notify remote peer that we don't know a channel he is talking about,
2411 * probably CHANNEL_DESTROY was missed.
2413 * @param t Tunnel on which to notify.
2414 * @param gid ID of the channel.
2417 send_channel_destroy (struct CadetTunnel *t, unsigned int gid)
2419 struct GNUNET_CADET_ChannelManage msg;
2421 msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_CHANNEL_DESTROY);
2422 msg.header.size = htons (sizeof (msg));
2423 msg.chid = htonl (gid);
2425 LOG (GNUNET_ERROR_TYPE_DEBUG,
2426 "WARNING destroying unknown channel %u on tunnel %s\n",
2428 send_prebuilt_message (&msg.header, t, NULL, GNUNET_YES, NULL, NULL, NULL);
2433 * Demultiplex data per channel and call appropriate channel handler.
2435 * @param t Tunnel on which the data came.
2436 * @param msg Data message.
2437 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
2438 * #GNUNET_YES if message is FWD on the respective channel (loopback)
2439 * #GNUNET_NO if message is BCK on the respective channel (loopback)
2440 * #GNUNET_SYSERR if message on a one-ended channel (remote)
2443 handle_data (struct CadetTunnel *t,
2444 const struct GNUNET_CADET_Data *msg,
2447 struct CadetChannel *ch;
2451 size = ntohs (msg->header.size);
2453 sizeof (struct GNUNET_CADET_Data) +
2454 sizeof (struct GNUNET_MessageHeader))
2459 LOG (GNUNET_ERROR_TYPE_DEBUG, " payload of type %s\n",
2460 GC_m2s (ntohs (msg[1].header.type)));
2463 ch = GCT_get_channel (t, ntohl (msg->chid));
2466 GNUNET_STATISTICS_update (stats, "# data on unknown channel",
2468 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel 0x%X unknown\n",
2470 send_channel_destroy (t, ntohl (msg->chid));
2474 GCCH_handle_data (ch, msg, fwd);
2479 * Demultiplex data ACKs per channel and update appropriate channel buffer info.
2481 * @param t Tunnel on which the DATA ACK came.
2482 * @param msg DATA ACK message.
2483 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
2484 * #GNUNET_YES if message is FWD on the respective channel (loopback)
2485 * #GNUNET_NO if message is BCK on the respective channel (loopback)
2486 * #GNUNET_SYSERR if message on a one-ended channel (remote)
2489 handle_data_ack (struct CadetTunnel *t,
2490 const struct GNUNET_CADET_DataACK *msg,
2493 struct CadetChannel *ch;
2497 size = ntohs (msg->header.size);
2498 if (size != sizeof (struct GNUNET_CADET_DataACK))
2505 ch = GCT_get_channel (t, ntohl (msg->chid));
2508 GNUNET_STATISTICS_update (stats, "# data ack on unknown channel",
2510 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel %u unknown\n",
2515 GCCH_handle_data_ack (ch, msg, fwd);
2520 * Handle channel create.
2522 * @param t Tunnel on which the data came.
2523 * @param msg Data message.
2526 handle_ch_create (struct CadetTunnel *t,
2527 const struct GNUNET_CADET_ChannelCreate *msg)
2529 struct CadetChannel *ch;
2533 size = ntohs (msg->header.size);
2534 if (size != sizeof (struct GNUNET_CADET_ChannelCreate))
2541 ch = GCT_get_channel (t, ntohl (msg->chid));
2542 if (NULL != ch && ! GCT_is_loopback (t))
2544 /* Probably a retransmission, safe to ignore */
2545 LOG (GNUNET_ERROR_TYPE_DEBUG, " already exists...\n");
2547 ch = GCCH_handle_create (t, msg);
2549 GCT_add_channel (t, ch);
2555 * Handle channel NACK: check correctness and call channel handler for NACKs.
2557 * @param t Tunnel on which the NACK came.
2558 * @param msg NACK message.
2561 handle_ch_nack (struct CadetTunnel *t,
2562 const struct GNUNET_CADET_ChannelManage *msg)
2564 struct CadetChannel *ch;
2568 size = ntohs (msg->header.size);
2569 if (size != sizeof (struct GNUNET_CADET_ChannelManage))
2576 ch = GCT_get_channel (t, ntohl (msg->chid));
2579 GNUNET_STATISTICS_update (stats, "# channel NACK on unknown channel",
2581 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel %u unknown\n",
2586 GCCH_handle_nack (ch);
2591 * Handle a CHANNEL ACK (SYNACK/ACK).
2593 * @param t Tunnel on which the CHANNEL ACK came.
2594 * @param msg CHANNEL ACK message.
2595 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
2596 * #GNUNET_YES if message is FWD on the respective channel (loopback)
2597 * #GNUNET_NO if message is BCK on the respective channel (loopback)
2598 * #GNUNET_SYSERR if message on a one-ended channel (remote)
2601 handle_ch_ack (struct CadetTunnel *t,
2602 const struct GNUNET_CADET_ChannelManage *msg,
2605 struct CadetChannel *ch;
2609 size = ntohs (msg->header.size);
2610 if (size != sizeof (struct GNUNET_CADET_ChannelManage))
2617 ch = GCT_get_channel (t, ntohl (msg->chid));
2620 GNUNET_STATISTICS_update (stats, "# channel ack on unknown channel",
2622 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel %u unknown\n",
2627 GCCH_handle_ack (ch, msg, fwd);
2632 * Handle a channel destruction message.
2634 * @param t Tunnel on which the message came.
2635 * @param msg Channel destroy message.
2636 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
2637 * #GNUNET_YES if message is FWD on the respective channel (loopback)
2638 * #GNUNET_NO if message is BCK on the respective channel (loopback)
2639 * #GNUNET_SYSERR if message on a one-ended channel (remote)
2642 handle_ch_destroy (struct CadetTunnel *t,
2643 const struct GNUNET_CADET_ChannelManage *msg,
2646 struct CadetChannel *ch;
2650 size = ntohs (msg->header.size);
2651 if (size != sizeof (struct GNUNET_CADET_ChannelManage))
2658 ch = GCT_get_channel (t, ntohl (msg->chid));
2661 /* Probably a retransmission, safe to ignore */
2665 GCCH_handle_destroy (ch, msg, fwd);
2670 * Free Axolotl data.
2675 destroy_ax (struct CadetTunnel *t)
2680 GNUNET_free_non_null (t->ax->DHRs);
2681 GNUNET_free_non_null (t->ax->kx_0);
2682 while (NULL != t->ax->skipped_head)
2683 delete_skipped_key (t, t->ax->skipped_head);
2684 GNUNET_assert (0 == t->ax->skipped);
2686 GNUNET_free (t->ax);
2689 if (NULL != t->rekey_task)
2691 GNUNET_SCHEDULER_cancel (t->rekey_task);
2692 t->rekey_task = NULL;
2694 if (NULL != t->ephm_h)
2696 GCC_cancel (t->ephm_h);
2703 * The peer's ephemeral key has changed: update the symmetrical keys.
2705 * @param t Tunnel this message came on.
2706 * @param msg Key eXchange message.
2709 handle_ephemeral (struct CadetTunnel *t,
2710 const struct GNUNET_CADET_KX_Ephemeral *msg)
2712 LOG (GNUNET_ERROR_TYPE_INFO, "<=== EPHM for %s\n", GCT_2s (t));
2714 if (GNUNET_OK != check_ephemeral (t, msg))
2716 GNUNET_break_op (0);
2720 /* If we get a proper OTR-style ephemeral, fallback to old crypto. */
2724 t->enc_type = CADET_OTR;
2725 if (NULL != t->rekey_task)
2726 GNUNET_SCHEDULER_cancel (t->rekey_task);
2727 if (GNUNET_OK != create_kx_ctx (t))
2733 rekey_tunnel (t, NULL);
2734 GNUNET_STATISTICS_update (stats, "# otr-downgrades", -1, GNUNET_NO);
2738 * If the key is different from what we know, derive the new E/D keys.
2739 * Else destroy the rekey ctx (duplicate EPHM after successful KX).
2741 if (0 != memcmp (&t->peers_ephemeral_key, &msg->ephemeral_key,
2742 sizeof (msg->ephemeral_key)))
2744 #if DUMP_KEYS_TO_STDERR
2745 LOG (GNUNET_ERROR_TYPE_INFO, "OLD: %s\n",
2746 GNUNET_h2s ((struct GNUNET_HashCode *) &t->peers_ephemeral_key));
2747 LOG (GNUNET_ERROR_TYPE_INFO, "NEW: %s\n",
2748 GNUNET_h2s ((struct GNUNET_HashCode *) &msg->ephemeral_key));
2750 t->peers_ephemeral_key = msg->ephemeral_key;
2752 if (GNUNET_OK != create_kx_ctx (t))
2759 if (CADET_TUNNEL_KEY_OK == t->estate)
2761 GCT_change_estate (t, CADET_TUNNEL_KEY_REKEY);
2763 if (NULL != t->rekey_task)
2764 GNUNET_SCHEDULER_cancel (t->rekey_task);
2765 t->rekey_task = GNUNET_SCHEDULER_add_now (rekey_tunnel, t);
2767 if (CADET_TUNNEL_KEY_SENT == t->estate)
2769 LOG (GNUNET_ERROR_TYPE_DEBUG, " our key was sent, sending challenge\n");
2771 GCT_change_estate (t, CADET_TUNNEL_KEY_PING);
2774 if (CADET_TUNNEL_KEY_UNINITIALIZED != ntohl(msg->sender_status))
2778 LOG (GNUNET_ERROR_TYPE_DEBUG, " recv nonce e %u\n", msg->nonce);
2779 t_decrypt (t, &nonce, &msg->nonce, ping_encryption_size (), msg->iv);
2780 LOG (GNUNET_ERROR_TYPE_DEBUG, " recv nonce c %u\n", nonce);
2781 send_pong (t, nonce);
2787 * Peer has answer to our challenge.
2788 * If answer is successful, consider the key exchange finished and clean
2789 * up all related state.
2791 * @param t Tunnel this message came on.
2792 * @param msg Key eXchange Pong message.
2795 handle_pong (struct CadetTunnel *t,
2796 const struct GNUNET_CADET_KX_Pong *msg)
2800 LOG (GNUNET_ERROR_TYPE_INFO, "<=== PONG for %s\n", GCT_2s (t));
2801 if (NULL == t->rekey_task)
2803 GNUNET_STATISTICS_update (stats, "# duplicate PONG messages", 1, GNUNET_NO);
2806 if (NULL == t->kx_ctx)
2808 GNUNET_STATISTICS_update (stats, "# stray PONG messages", 1, GNUNET_NO);
2812 t_decrypt (t, &challenge, &msg->nonce, sizeof (uint32_t), msg->iv);
2813 if (challenge != t->kx_ctx->challenge)
2815 LOG (GNUNET_ERROR_TYPE_WARNING, "Wrong PONG challenge on %s\n", GCT_2s (t));
2816 LOG (GNUNET_ERROR_TYPE_DEBUG, "PONG: %u (e: %u). Expected: %u.\n",
2817 challenge, msg->nonce, t->kx_ctx->challenge);
2821 GNUNET_SCHEDULER_cancel (t->rekey_task);
2822 t->rekey_task = NULL;
2824 /* Don't free the old keys right away, but after a delay.
2825 * Rationale: the KX could have happened over a very fast connection,
2826 * with payload traffic still signed with the old key stuck in a slower
2828 * Don't keep the keys longer than 1/4 the rekey period, and no longer than
2832 GCT_change_estate (t, CADET_TUNNEL_KEY_OK);
2837 * Handle Axolotl handshake.
2839 * @param t Tunnel this message came on.
2840 * @param msg Key eXchange Pong message.
2843 handle_kx_ax (struct CadetTunnel *t, const struct GNUNET_CADET_AX_KX *msg)
2845 struct CadetTunnelAxolotl *ax;
2846 struct GNUNET_HashCode key_material[3];
2847 struct GNUNET_CRYPTO_SymmetricSessionKey keys[5];
2848 const char salt[] = "CADET Axolotl salt";
2849 const struct GNUNET_PeerIdentity *pid;
2852 LOG (GNUNET_ERROR_TYPE_INFO, "<=== AX_KX on %s\n", GCT_2s (t));
2856 /* Something is wrong if ax is NULL. Whose fault it is? */
2857 GNUNET_break_op (CADET_OTR == t->enc_type);
2858 GNUNET_break (CADET_Axolotl == t->enc_type);
2862 pid = GCT_get_destination (t);
2863 if (0 > GNUNET_CRYPTO_cmp_peer_identity (&my_full_id, pid))
2864 am_I_alice = GNUNET_YES;
2865 else if (0 < GNUNET_CRYPTO_cmp_peer_identity (&my_full_id, pid))
2866 am_I_alice = GNUNET_NO;
2869 GNUNET_break_op (0);
2873 if (GNUNET_CADET_AX_KX_FLAG_FORCE_REPLY ==
2874 (GNUNET_CADET_AX_KX_FLAG_FORCE_REPLY & ntohl (msg->flags)))
2875 GCT_send_ax_kx (t, GNUNET_NO);
2877 if (CADET_TUNNEL_KEY_OK == t->estate)
2880 LOG (GNUNET_ERROR_TYPE_INFO, " is Alice? %s\n", am_I_alice ? "YES" : "NO");
2883 ax->DHRr = msg->ratchet_key;
2886 if (GNUNET_YES == am_I_alice)
2888 GNUNET_CRYPTO_eddsa_ecdh (id_key, /* A */
2889 &msg->ephemeral_key, /* B0 */
2894 GNUNET_CRYPTO_ecdh_eddsa (ax->kx_0, /* B0 */
2895 &pid->public_key, /* A */
2900 if (GNUNET_YES == am_I_alice)
2902 GNUNET_CRYPTO_ecdh_eddsa (ax->kx_0, /* A0 */
2903 &pid->public_key, /* B */
2908 GNUNET_CRYPTO_eddsa_ecdh (id_key, /* A */
2909 &msg->ephemeral_key, /* B0 */
2916 /* (This is the triple-DH, we could probably safely skip this,
2917 as A0/B0 are already in the key material.) */
2918 GNUNET_CRYPTO_ecc_ecdh (ax->kx_0, /* A0 or B0 */
2919 &msg->ephemeral_key, /* B0 or A0 */
2922 #if DUMP_KEYS_TO_STDERR
2925 for (i = 0; i < 3; i++)
2926 LOG (GNUNET_ERROR_TYPE_INFO, "km[%u]: %s\n",
2927 i, GNUNET_h2s (&key_material[i]));
2932 GNUNET_CRYPTO_kdf (keys, sizeof (keys),
2933 salt, sizeof (salt),
2934 &key_material, sizeof (key_material), NULL);
2937 if (GNUNET_YES == am_I_alice)
2943 ax->ratchet_flag = GNUNET_YES;
2951 ax->ratchet_flag = GNUNET_NO;
2952 ax->ratchet_allowed = GNUNET_NO;
2953 ax->ratchet_counter = 0;
2954 ax->ratchet_expiration =
2955 GNUNET_TIME_absolute_add (GNUNET_TIME_absolute_get(), ratchet_time);
2957 GCT_change_estate (t, CADET_TUNNEL_KEY_OK);
2962 * Demultiplex by message type and call appropriate handler for a message
2963 * towards a channel of a local tunnel.
2965 * @param t Tunnel this message came on.
2966 * @param msgh Message header.
2967 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
2968 * #GNUNET_YES if message is FWD on the respective channel (loopback)
2969 * #GNUNET_NO if message is BCK on the respective channel (loopback)
2970 * #GNUNET_SYSERR if message on a one-ended channel (remote)
2973 handle_decrypted (struct CadetTunnel *t,
2974 const struct GNUNET_MessageHeader *msgh,
2979 type = ntohs (msgh->type);
2980 LOG (GNUNET_ERROR_TYPE_INFO, "<=== %s on %s\n", GC_m2s (type), GCT_2s (t));
2984 case GNUNET_MESSAGE_TYPE_CADET_KEEPALIVE:
2985 /* Do nothing, connection aleady got updated. */
2986 GNUNET_STATISTICS_update (stats, "# keepalives received", 1, GNUNET_NO);
2989 case GNUNET_MESSAGE_TYPE_CADET_DATA:
2990 /* Don't send hop ACK, wait for client to ACK */
2991 handle_data (t, (struct GNUNET_CADET_Data *) msgh, fwd);
2994 case GNUNET_MESSAGE_TYPE_CADET_DATA_ACK:
2995 handle_data_ack (t, (struct GNUNET_CADET_DataACK *) msgh, fwd);
2998 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_CREATE:
2999 handle_ch_create (t, (struct GNUNET_CADET_ChannelCreate *) msgh);
3002 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_NACK:
3003 handle_ch_nack (t, (struct GNUNET_CADET_ChannelManage *) msgh);
3006 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_ACK:
3007 handle_ch_ack (t, (struct GNUNET_CADET_ChannelManage *) msgh, fwd);
3010 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_DESTROY:
3011 handle_ch_destroy (t, (struct GNUNET_CADET_ChannelManage *) msgh, fwd);
3015 GNUNET_break_op (0);
3016 LOG (GNUNET_ERROR_TYPE_WARNING,
3017 "end-to-end message not known (%u)\n",
3018 ntohs (msgh->type));
3019 GCT_debug (t, GNUNET_ERROR_TYPE_WARNING);
3023 /******************************************************************************/
3024 /******************************** API ***********************************/
3025 /******************************************************************************/
3027 * Decrypt old format and demultiplex by message type. Call appropriate handler
3028 * for a message towards a channel of a local tunnel.
3030 * @param t Tunnel this message came on.
3031 * @param msg Message header.
3034 GCT_handle_encrypted (struct CadetTunnel *t,
3035 const struct GNUNET_MessageHeader *msg)
3037 uint16_t size = ntohs (msg->size);
3039 size_t payload_size;
3042 const struct GNUNET_MessageHeader *msgh;
3045 type = ntohs (msg->type);
3048 case GNUNET_MESSAGE_TYPE_CADET_ENCRYPTED:
3050 const struct GNUNET_CADET_Encrypted *emsg;
3052 emsg = (const struct GNUNET_CADET_Encrypted *) msg;
3053 payload_size = size - sizeof (struct GNUNET_CADET_Encrypted);
3054 decrypted_size = t_decrypt_and_validate (t, cbuf, &emsg[1], payload_size,
3055 emsg->iv, &emsg->hmac);
3058 case GNUNET_MESSAGE_TYPE_CADET_AX:
3060 const struct GNUNET_CADET_AX *emsg;
3062 emsg = (const struct GNUNET_CADET_AX *) msg;
3063 decrypted_size = t_ax_decrypt_and_validate (t, cbuf, emsg, size);
3067 GNUNET_break_op (0);
3070 if (-1 == decrypted_size)
3072 GNUNET_break_op (0);
3076 /* FIXME: this is bad, as the structs returned from
3077 this loop may be unaligned, see util's MST for
3078 how to do this right. */
3080 while (off < decrypted_size)
3084 msgh = (const struct GNUNET_MessageHeader *) &cbuf[off];
3085 msize = ntohs (msgh->size);
3086 if (msize < sizeof (struct GNUNET_MessageHeader))
3088 GNUNET_break_op (0);
3091 handle_decrypted (t, msgh, GNUNET_SYSERR);
3098 * Demultiplex an encapsulated KX message by message type.
3100 * @param t Tunnel on which the message came.
3101 * @param message Payload of KX message.
3104 GCT_handle_kx (struct CadetTunnel *t,
3105 const struct GNUNET_MessageHeader *message)
3109 type = ntohs (message->type);
3110 LOG (GNUNET_ERROR_TYPE_DEBUG, "kx message received: %s\n", GC_m2s (type));
3113 case GNUNET_MESSAGE_TYPE_CADET_KX_EPHEMERAL:
3114 handle_ephemeral (t, (const struct GNUNET_CADET_KX_Ephemeral *) message);
3117 case GNUNET_MESSAGE_TYPE_CADET_KX_PONG:
3118 handle_pong (t, (const struct GNUNET_CADET_KX_Pong *) message);
3121 case GNUNET_MESSAGE_TYPE_CADET_AX_KX:
3122 handle_kx_ax (t, (const struct GNUNET_CADET_AX_KX *) message);
3126 GNUNET_break_op (0);
3127 LOG (GNUNET_ERROR_TYPE_WARNING, "kx message %s unknown\n", GC_m2s (type));
3132 * Initialize the tunnel subsystem.
3134 * @param c Configuration handle.
3135 * @param key ECC private key, to derive all other keys and do crypto.
3138 GCT_init (const struct GNUNET_CONFIGURATION_Handle *c,
3139 const struct GNUNET_CRYPTO_EddsaPrivateKey *key)
3141 int expected_overhead;
3143 LOG (GNUNET_ERROR_TYPE_DEBUG, "init\n");
3145 expected_overhead = 0;
3146 expected_overhead += sizeof (struct GNUNET_CADET_Encrypted);
3147 expected_overhead += sizeof (struct GNUNET_CADET_Data);
3148 expected_overhead += sizeof (struct GNUNET_CADET_ACK);
3149 GNUNET_assert (GNUNET_CONSTANTS_CADET_P2P_OVERHEAD == expected_overhead);
3152 GNUNET_CONFIGURATION_get_value_number (c, "CADET", "DEFAULT_TTL",
3155 GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_DEBUG,
3156 "CADET", "DEFAULT_TTL", "USING DEFAULT");
3160 GNUNET_CONFIGURATION_get_value_time (c, "CADET", "REKEY_PERIOD",
3163 rekey_period = GNUNET_TIME_UNIT_DAYS;
3166 GNUNET_CONFIGURATION_get_value_number (c, "CADET", "RATCHET_MESSAGES",
3169 GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_WARNING,
3170 "CADET", "RATCHET_MESSAGES", "USING DEFAULT");
3171 ratchet_messages = 64;
3174 GNUNET_CONFIGURATION_get_value_time (c, "CADET", "RATCHET_TIME",
3177 GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_WARNING,
3178 "CADET", "RATCHET_TIME", "USING DEFAULT");
3179 ratchet_time = GNUNET_TIME_UNIT_HOURS;
3185 otr_kx_msg.header.size = htons (sizeof (otr_kx_msg));
3186 otr_kx_msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_KX_EPHEMERAL);
3187 otr_kx_msg.purpose.purpose = htonl (GNUNET_SIGNATURE_PURPOSE_CADET_KX);
3188 otr_kx_msg.purpose.size = htonl (ephemeral_purpose_size ());
3189 otr_kx_msg.origin_identity = my_full_id;
3190 rekey_task = GNUNET_SCHEDULER_add_now (&global_otr_rekey, NULL);
3191 tunnels = GNUNET_CONTAINER_multipeermap_create (128, GNUNET_YES);
3196 * Shut down the tunnel subsystem.
3201 if (NULL != rekey_task)
3203 GNUNET_SCHEDULER_cancel (rekey_task);
3206 GNUNET_CONTAINER_multipeermap_iterate (tunnels, &destroy_iterator, NULL);
3207 GNUNET_CONTAINER_multipeermap_destroy (tunnels);
3214 * @param destination Peer this tunnel is towards.
3216 struct CadetTunnel *
3217 GCT_new (struct CadetPeer *destination)
3219 struct CadetTunnel *t;
3221 t = GNUNET_new (struct CadetTunnel);
3223 t->peer = destination;
3226 GNUNET_CONTAINER_multipeermap_put (tunnels, GCP_get_id (destination), t,
3227 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_FAST))
3233 t->ax = GNUNET_new (struct CadetTunnelAxolotl);
3235 t->ax->kx_0 = GNUNET_CRYPTO_ecdhe_key_create ();
3241 * Change the tunnel's connection state.
3243 * @param t Tunnel whose connection state to change.
3244 * @param cstate New connection state.
3247 GCT_change_cstate (struct CadetTunnel* t, enum CadetTunnelCState cstate)
3251 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s cstate %s => %s\n",
3252 GCP_2s (t->peer), cstate2s (t->cstate), cstate2s (cstate));
3253 if (myid != GCP_get_short_id (t->peer) &&
3254 CADET_TUNNEL_READY != t->cstate &&
3255 CADET_TUNNEL_READY == cstate)
3258 if (CADET_TUNNEL_KEY_OK == t->estate)
3260 LOG (GNUNET_ERROR_TYPE_DEBUG, " cstate triggered send queued data\n");
3261 send_queued_data (t);
3263 else if (CADET_TUNNEL_KEY_UNINITIALIZED == t->estate)
3265 LOG (GNUNET_ERROR_TYPE_DEBUG, " cstate triggered kx\n");
3266 GCT_send_ax_kx (t, GNUNET_NO);
3270 LOG (GNUNET_ERROR_TYPE_DEBUG, "estate %s\n", estate2s (t->estate));
3275 if (CADET_TUNNEL_READY == cstate
3276 && CONNECTIONS_PER_TUNNEL <= GCT_count_connections (t))
3278 LOG (GNUNET_ERROR_TYPE_DEBUG, " cstate triggered stop dht\n");
3279 GCP_stop_search (t->peer);
3285 * Change the tunnel encryption state.
3287 * @param t Tunnel whose encryption state to change, or NULL.
3288 * @param state New encryption state.
3291 GCT_change_estate (struct CadetTunnel* t, enum CadetTunnelEState state)
3293 enum CadetTunnelEState old;
3300 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s estate was %s\n",
3301 GCP_2s (t->peer), estate2s (old));
3302 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s estate is now %s\n",
3303 GCP_2s (t->peer), estate2s (t->estate));
3305 /* Send queued data if enc state changes to OK */
3306 if (myid != GCP_get_short_id (t->peer) &&
3307 CADET_TUNNEL_KEY_OK != old && CADET_TUNNEL_KEY_OK == t->estate)
3309 send_queued_data (t);
3315 * @brief Check if tunnel has too many connections, and remove one if necessary.
3317 * Currently this means the newest connection, unless it is a direct one.
3318 * Implemented as a task to avoid freeing a connection that is in the middle
3319 * of being created/processed.
3321 * @param cls Closure (Tunnel to check).
3322 * @param tc Task context.
3325 trim_connections (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
3327 struct CadetTunnel *t = cls;
3329 t->trim_connections_task = NULL;
3331 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
3334 if (GCT_count_connections (t) > 2 * CONNECTIONS_PER_TUNNEL)
3336 struct CadetTConnection *iter;
3337 struct CadetTConnection *c;
3339 for (c = iter = t->connection_head; NULL != iter; iter = iter->next)
3341 if ((iter->created.abs_value_us > c->created.abs_value_us)
3342 && GNUNET_NO == GCC_is_direct (iter->c))
3349 LOG (GNUNET_ERROR_TYPE_DEBUG, "Too many connections on tunnel %s\n",
3351 LOG (GNUNET_ERROR_TYPE_DEBUG, "Destroying connection %s\n",
3364 * Add a connection to a tunnel.
3367 * @param c Connection.
3370 GCT_add_connection (struct CadetTunnel *t, struct CadetConnection *c)
3372 struct CadetTConnection *aux;
3374 GNUNET_assert (NULL != c);
3376 LOG (GNUNET_ERROR_TYPE_DEBUG, "add connection %s\n", GCC_2s (c));
3377 LOG (GNUNET_ERROR_TYPE_DEBUG, " to tunnel %s\n", GCT_2s (t));
3378 for (aux = t->connection_head; aux != NULL; aux = aux->next)
3382 aux = GNUNET_new (struct CadetTConnection);
3384 aux->created = GNUNET_TIME_absolute_get ();
3386 GNUNET_CONTAINER_DLL_insert (t->connection_head, t->connection_tail, aux);
3388 if (CADET_TUNNEL_SEARCHING == t->cstate)
3389 GCT_change_cstate (t, CADET_TUNNEL_WAITING);
3391 if (NULL != t->trim_connections_task)
3392 t->trim_connections_task = GNUNET_SCHEDULER_add_now (&trim_connections, t);
3397 * Remove a connection from a tunnel.
3400 * @param c Connection.
3403 GCT_remove_connection (struct CadetTunnel *t,
3404 struct CadetConnection *c)
3406 struct CadetTConnection *aux;
3407 struct CadetTConnection *next;
3410 LOG (GNUNET_ERROR_TYPE_DEBUG, "Removing connection %s from tunnel %s\n",
3411 GCC_2s (c), GCT_2s (t));
3412 for (aux = t->connection_head; aux != NULL; aux = next)
3417 GNUNET_CONTAINER_DLL_remove (t->connection_head, t->connection_tail, aux);
3422 conns = GCT_count_connections (t);
3424 && NULL == t->destroy_task
3425 && CADET_TUNNEL_SHUTDOWN != t->cstate
3426 && GNUNET_NO == shutting_down)
3428 if (0 == GCT_count_any_connections (t))
3429 GCT_change_cstate (t, CADET_TUNNEL_SEARCHING);
3431 GCT_change_cstate (t, CADET_TUNNEL_WAITING);
3434 /* Start new connections if needed */
3435 if (CONNECTIONS_PER_TUNNEL > conns
3436 && NULL == t->destroy_task
3437 && CADET_TUNNEL_SHUTDOWN != t->cstate
3438 && GNUNET_NO == shutting_down)
3440 LOG (GNUNET_ERROR_TYPE_DEBUG, " too few connections, getting new ones\n");
3441 GCP_connect (t->peer); /* Will change cstate to WAITING when possible */
3445 /* If not marked as ready, no change is needed */
3446 if (CADET_TUNNEL_READY != t->cstate)
3449 /* Check if any connection is ready to maintain cstate */
3450 for (aux = t->connection_head; aux != NULL; aux = aux->next)
3451 if (CADET_CONNECTION_READY == GCC_get_state (aux->c))
3457 * Add a channel to a tunnel.
3460 * @param ch Channel.
3463 GCT_add_channel (struct CadetTunnel *t, struct CadetChannel *ch)
3465 struct CadetTChannel *aux;
3467 GNUNET_assert (NULL != ch);
3469 LOG (GNUNET_ERROR_TYPE_DEBUG, "Adding channel %p to tunnel %p\n", ch, t);
3471 for (aux = t->channel_head; aux != NULL; aux = aux->next)
3473 LOG (GNUNET_ERROR_TYPE_DEBUG, " already there %p\n", aux->ch);
3478 aux = GNUNET_new (struct CadetTChannel);
3480 LOG (GNUNET_ERROR_TYPE_DEBUG, " adding %p to %p\n", aux, t->channel_head);
3481 GNUNET_CONTAINER_DLL_insert_tail (t->channel_head, t->channel_tail, aux);
3483 if (NULL != t->destroy_task)
3485 GNUNET_SCHEDULER_cancel (t->destroy_task);
3486 t->destroy_task = NULL;
3487 LOG (GNUNET_ERROR_TYPE_DEBUG, " undo destroy!\n");
3493 * Remove a channel from a tunnel.
3496 * @param ch Channel.
3499 GCT_remove_channel (struct CadetTunnel *t, struct CadetChannel *ch)
3501 struct CadetTChannel *aux;
3503 LOG (GNUNET_ERROR_TYPE_DEBUG, "Removing channel %p from tunnel %p\n", ch, t);
3504 for (aux = t->channel_head; aux != NULL; aux = aux->next)
3508 LOG (GNUNET_ERROR_TYPE_DEBUG, " found! %s\n", GCCH_2s (ch));
3509 GNUNET_CONTAINER_DLL_remove (t->channel_head, t->channel_tail, aux);
3518 * Search for a channel by global ID.
3520 * @param t Tunnel containing the channel.
3521 * @param chid Public channel number.
3523 * @return channel handler, NULL if doesn't exist
3525 struct CadetChannel *
3526 GCT_get_channel (struct CadetTunnel *t, CADET_ChannelNumber chid)
3528 struct CadetTChannel *iter;
3533 for (iter = t->channel_head; NULL != iter; iter = iter->next)
3535 if (GCCH_get_id (iter->ch) == chid)
3539 return NULL == iter ? NULL : iter->ch;
3544 * @brief Destroy a tunnel and free all resources.
3546 * Should only be called a while after the tunnel has been marked as destroyed,
3547 * in case there is a new channel added to the same peer shortly after marking
3548 * the tunnel. This way we avoid a new public key handshake.
3550 * @param cls Closure (tunnel to destroy).
3551 * @param tc Task context.
3554 delayed_destroy (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
3556 struct CadetTunnel *t = cls;
3557 struct CadetTConnection *iter;
3559 LOG (GNUNET_ERROR_TYPE_DEBUG, "delayed destroying tunnel %p\n", t);
3560 if (0 != (GNUNET_SCHEDULER_REASON_SHUTDOWN & tc->reason))
3562 LOG (GNUNET_ERROR_TYPE_WARNING,
3563 "Not destroying tunnel, due to shutdown. "
3564 "Tunnel at %p should have been freed by GCT_shutdown\n", t);
3567 t->destroy_task = NULL;
3568 t->cstate = CADET_TUNNEL_SHUTDOWN;
3570 for (iter = t->connection_head; NULL != iter; iter = iter->next)
3572 GCC_send_destroy (iter->c);
3579 * Tunnel is empty: destroy it.
3581 * Notifies all connections about the destruction.
3583 * @param t Tunnel to destroy.
3586 GCT_destroy_empty (struct CadetTunnel *t)
3588 if (GNUNET_YES == shutting_down)
3589 return; /* Will be destroyed immediately anyway */
3591 if (NULL != t->destroy_task)
3593 LOG (GNUNET_ERROR_TYPE_WARNING,
3594 "Tunnel %s is already scheduled for destruction. Tunnel debug dump:\n",
3596 GCT_debug (t, GNUNET_ERROR_TYPE_WARNING);
3598 /* should never happen, tunnel can only become empty once, and the
3599 * task identifier should be NO_TASK (cleaned when the tunnel was created
3600 * or became un-empty)
3605 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s empty: scheduling destruction\n",
3608 // FIXME make delay a config option
3609 t->destroy_task = GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_MINUTES,
3610 &delayed_destroy, t);
3611 LOG (GNUNET_ERROR_TYPE_DEBUG, "Scheduled destroy of %p as %llu\n",
3612 t, t->destroy_task);
3617 * Destroy tunnel if empty (no more channels).
3619 * @param t Tunnel to destroy if empty.
3622 GCT_destroy_if_empty (struct CadetTunnel *t)
3624 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s destroy if empty\n", GCT_2s (t));
3625 if (0 < GCT_count_channels (t))
3628 GCT_destroy_empty (t);
3633 * Destroy the tunnel.
3635 * This function does not generate any warning traffic to clients or peers.
3638 * Cancel messages belonging to this tunnel queued to neighbors.
3639 * Free any allocated resources linked to the tunnel.
3641 * @param t The tunnel to destroy.
3644 GCT_destroy (struct CadetTunnel *t)
3646 struct CadetTConnection *iter_c;
3647 struct CadetTConnection *next_c;
3648 struct CadetTChannel *iter_ch;
3649 struct CadetTChannel *next_ch;
3654 LOG (GNUNET_ERROR_TYPE_DEBUG, "destroying tunnel %s\n", GCP_2s (t->peer));
3656 GNUNET_break (GNUNET_YES ==
3657 GNUNET_CONTAINER_multipeermap_remove (tunnels,
3658 GCP_get_id (t->peer), t));
3660 while (NULL != t->tq_head)
3661 unqueue_data (t->tq_head);
3663 for (iter_c = t->connection_head; NULL != iter_c; iter_c = next_c)
3665 next_c = iter_c->next;
3666 GCC_destroy (iter_c->c);
3668 for (iter_ch = t->channel_head; NULL != iter_ch; iter_ch = next_ch)
3670 next_ch = iter_ch->next;
3671 GCCH_destroy (iter_ch->ch);
3672 /* Should only happen on shutdown, but it's ok. */
3675 if (NULL != t->destroy_task)
3677 LOG (GNUNET_ERROR_TYPE_DEBUG, "cancelling dest: %llX\n", t->destroy_task);
3678 GNUNET_SCHEDULER_cancel (t->destroy_task);
3679 t->destroy_task = NULL;
3682 if (NULL != t->trim_connections_task)
3684 LOG (GNUNET_ERROR_TYPE_DEBUG, "cancelling trim: %llX\n",
3685 t->trim_connections_task);
3686 GNUNET_SCHEDULER_cancel (t->trim_connections_task);
3687 t->trim_connections_task = NULL;
3690 GNUNET_STATISTICS_update (stats, "# tunnels", -1, GNUNET_NO);
3691 GCP_set_tunnel (t->peer, NULL);
3693 if (NULL != t->rekey_task)
3695 GNUNET_SCHEDULER_cancel (t->rekey_task);
3696 t->rekey_task = NULL;
3698 if (NULL != t->kx_ctx)
3700 if (NULL != t->kx_ctx->finish_task)
3701 GNUNET_SCHEDULER_cancel (t->kx_ctx->finish_task);
3702 GNUNET_free (t->kx_ctx);
3713 * @brief Use the given path for the tunnel.
3714 * Update the next and prev hops (and RCs).
3715 * (Re)start the path refresh in case the tunnel is locally owned.
3717 * @param t Tunnel to update.
3718 * @param p Path to use.
3720 * @return Connection created.
3722 struct CadetConnection *
3723 GCT_use_path (struct CadetTunnel *t, struct CadetPeerPath *p)
3725 struct CadetConnection *c;
3726 struct GNUNET_CADET_Hash cid;
3727 unsigned int own_pos;
3729 if (NULL == t || NULL == p)
3735 if (CADET_TUNNEL_SHUTDOWN == t->cstate)
3741 for (own_pos = 0; own_pos < p->length; own_pos++)
3743 if (p->peers[own_pos] == myid)
3746 if (own_pos >= p->length)
3748 GNUNET_break_op (0);
3752 GNUNET_CRYPTO_random_block (GNUNET_CRYPTO_QUALITY_NONCE, &cid, sizeof (cid));
3753 c = GCC_new (&cid, t, p, own_pos);
3756 /* Path was flawed */
3759 GCT_add_connection (t, c);
3765 * Count all created connections of a tunnel. Not necessarily ready connections!
3767 * @param t Tunnel on which to count.
3769 * @return Number of connections created, either being established or ready.
3772 GCT_count_any_connections (struct CadetTunnel *t)
3774 struct CadetTConnection *iter;
3780 for (count = 0, iter = t->connection_head; NULL != iter; iter = iter->next)
3788 * Count established (ready) connections of a tunnel.
3790 * @param t Tunnel on which to count.
3792 * @return Number of connections.
3795 GCT_count_connections (struct CadetTunnel *t)
3797 struct CadetTConnection *iter;
3803 for (count = 0, iter = t->connection_head; NULL != iter; iter = iter->next)
3804 if (CADET_CONNECTION_READY == GCC_get_state (iter->c))
3812 * Count channels of a tunnel.
3814 * @param t Tunnel on which to count.
3816 * @return Number of channels.
3819 GCT_count_channels (struct CadetTunnel *t)
3821 struct CadetTChannel *iter;
3824 for (count = 0, iter = t->channel_head;
3826 iter = iter->next, count++) /* skip */;
3833 * Get the connectivity state of a tunnel.
3837 * @return Tunnel's connectivity state.
3839 enum CadetTunnelCState
3840 GCT_get_cstate (struct CadetTunnel *t)
3845 return (enum CadetTunnelCState) -1;
3852 * Get the encryption state of a tunnel.
3856 * @return Tunnel's encryption state.
3858 enum CadetTunnelEState
3859 GCT_get_estate (struct CadetTunnel *t)
3864 return (enum CadetTunnelEState) -1;
3870 * Get the maximum buffer space for a tunnel towards a local client.
3874 * @return Biggest buffer space offered by any channel in the tunnel.
3877 GCT_get_channels_buffer (struct CadetTunnel *t)
3879 struct CadetTChannel *iter;
3880 unsigned int buffer;
3881 unsigned int ch_buf;
3883 if (NULL == t->channel_head)
3885 /* Probably getting buffer for a channel create/handshake. */
3886 LOG (GNUNET_ERROR_TYPE_DEBUG, " no channels, allow max\n");
3887 return MIN_TUNNEL_BUFFER;
3891 for (iter = t->channel_head; NULL != iter; iter = iter->next)
3893 ch_buf = get_channel_buffer (iter);
3894 if (ch_buf > buffer)
3897 if (MIN_TUNNEL_BUFFER > buffer)
3898 return MIN_TUNNEL_BUFFER;
3900 if (MAX_TUNNEL_BUFFER < buffer)
3903 return MAX_TUNNEL_BUFFER;
3910 * Get the total buffer space for a tunnel for P2P traffic.
3914 * @return Buffer space offered by all connections in the tunnel.
3917 GCT_get_connections_buffer (struct CadetTunnel *t)
3919 struct CadetTConnection *iter;
3920 unsigned int buffer;
3922 if (GNUNET_NO == is_ready (t))
3924 if (count_queued_data (t) >= 3)
3931 for (iter = t->connection_head; NULL != iter; iter = iter->next)
3933 if (GCC_get_state (iter->c) != CADET_CONNECTION_READY)
3937 buffer += get_connection_buffer (iter);
3945 * Get the tunnel's destination.
3949 * @return ID of the destination peer.
3951 const struct GNUNET_PeerIdentity *
3952 GCT_get_destination (struct CadetTunnel *t)
3954 return GCP_get_id (t->peer);
3959 * Get the tunnel's next free global channel ID.
3963 * @return GID of a channel free to use.
3966 GCT_get_next_chid (struct CadetTunnel *t)
3968 CADET_ChannelNumber chid;
3969 CADET_ChannelNumber mask;
3972 /* Set bit 30 depending on the ID relationship. Bit 31 is always 0 for GID.
3973 * If our ID is bigger or loopback tunnel, start at 0, bit 30 = 0
3974 * If peer's ID is bigger, start at 0x4... bit 30 = 1
3976 result = GNUNET_CRYPTO_cmp_peer_identity (&my_full_id, GCP_get_id (t->peer));
3981 t->next_chid |= mask;
3983 while (NULL != GCT_get_channel (t, t->next_chid))
3985 LOG (GNUNET_ERROR_TYPE_DEBUG, "Channel %u exists...\n", t->next_chid);
3986 t->next_chid = (t->next_chid + 1) & ~GNUNET_CADET_LOCAL_CHANNEL_ID_CLI;
3987 t->next_chid |= mask;
3989 chid = t->next_chid;
3990 t->next_chid = (t->next_chid + 1) & ~GNUNET_CADET_LOCAL_CHANNEL_ID_CLI;
3991 t->next_chid |= mask;
3998 * Send ACK on one or more channels due to buffer in connections.
4000 * @param t Channel which has some free buffer space.
4003 GCT_unchoke_channels (struct CadetTunnel *t)
4005 struct CadetTChannel *iter;
4006 unsigned int buffer;
4007 unsigned int channels = GCT_count_channels (t);
4008 unsigned int choked_n;
4009 struct CadetChannel *choked[channels];
4011 LOG (GNUNET_ERROR_TYPE_DEBUG, "GCT_unchoke_channels on %s\n", GCT_2s (t));
4012 LOG (GNUNET_ERROR_TYPE_DEBUG, " head: %p\n", t->channel_head);
4013 if (NULL != t->channel_head)
4014 LOG (GNUNET_ERROR_TYPE_DEBUG, " head ch: %p\n", t->channel_head->ch);
4016 if (NULL != t->tq_head)
4017 send_queued_data (t);
4019 /* Get buffer space */
4020 buffer = GCT_get_connections_buffer (t);
4026 /* Count and remember choked channels */
4028 for (iter = t->channel_head; NULL != iter; iter = iter->next)
4030 if (GNUNET_NO == get_channel_allowed (iter))
4032 choked[choked_n++] = iter->ch;
4036 /* Unchoke random channels */
4037 while (0 < buffer && 0 < choked_n)
4039 unsigned int r = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK,
4041 GCCH_allow_client (choked[r], GCCH_is_origin (choked[r], GNUNET_YES));
4044 choked[r] = choked[choked_n];
4050 * Send ACK on one or more connections due to buffer space to the client.
4052 * Iterates all connections of the tunnel and sends ACKs appropriately.
4057 GCT_send_connection_acks (struct CadetTunnel *t)
4059 struct CadetTConnection *iter;
4062 uint32_t allow_per_connection;
4064 unsigned int buffer;
4066 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel send connection ACKs on %s\n",
4075 if (CADET_TUNNEL_READY != t->cstate)
4078 buffer = GCT_get_channels_buffer (t);
4079 LOG (GNUNET_ERROR_TYPE_DEBUG, " buffer %u\n", buffer);
4081 /* Count connections, how many messages are already allowed */
4082 cs = GCT_count_connections (t);
4083 for (allowed = 0, iter = t->connection_head; NULL != iter; iter = iter->next)
4085 allowed += get_connection_allowed (iter);
4087 LOG (GNUNET_ERROR_TYPE_DEBUG, " allowed %u\n", allowed);
4089 /* Make sure there is no overflow */
4090 if (allowed > buffer)
4093 /* Authorize connections to send more data */
4094 to_allow = buffer - allowed;
4096 for (iter = t->connection_head;
4097 NULL != iter && to_allow > 0;
4100 if (CADET_CONNECTION_READY != GCC_get_state (iter->c)
4101 || get_connection_allowed (iter) > 64 / 3)
4105 allow_per_connection = to_allow/cs;
4106 to_allow -= allow_per_connection;
4108 GCC_allow (iter->c, allow_per_connection,
4109 GCC_is_origin (iter->c, GNUNET_NO));
4114 /* Since we don't allow if it's allowed to send 64/3, this can happen. */
4115 LOG (GNUNET_ERROR_TYPE_DEBUG, " reminding to_allow: %u\n", to_allow);
4121 * Cancel a previously sent message while it's in the queue.
4123 * ONLY can be called before the continuation given to the send function
4124 * is called. Once the continuation is called, the message is no longer in the
4127 * @param q Handle to the queue.
4130 GCT_cancel (struct CadetTunnelQueue *q)
4134 GNUNET_assert (NULL == q->tqd);
4136 /* tun_message_sent() will be called and free q */
4138 else if (NULL != q->tqd)
4140 unqueue_data (q->tqd);
4142 if (NULL != q->cont)
4143 q->cont (q->cont_cls, NULL, q, 0, 0);
4154 * Sends an already built message on a tunnel, encrypting it and
4155 * choosing the best connection if not provided.
4157 * @param message Message to send. Function modifies it.
4158 * @param t Tunnel on which this message is transmitted.
4159 * @param c Connection to use (autoselect if NULL).
4160 * @param force Force the tunnel to take the message (buffer overfill).
4161 * @param cont Continuation to call once message is really sent.
4162 * @param cont_cls Closure for @c cont.
4164 * @return Handle to cancel message. NULL if @c cont is NULL.
4166 struct CadetTunnelQueue *
4167 GCT_send_prebuilt_message (const struct GNUNET_MessageHeader *message,
4168 struct CadetTunnel *t, struct CadetConnection *c,
4169 int force, GCT_sent cont, void *cont_cls)
4171 return send_prebuilt_message (message, t, c, force, cont, cont_cls, NULL);
4176 * Send an Axolotl KX message.
4178 * @param t Tunnel on which to send it.
4179 * @param force_reply Force the other peer to reply with a KX message.
4182 GCT_send_ax_kx (struct CadetTunnel *t, int force_reply)
4184 struct GNUNET_CADET_AX_KX msg;
4185 enum GNUNET_CADET_AX_KX_Flags flags;
4187 LOG (GNUNET_ERROR_TYPE_INFO, "===> AX_KX for %s\n", GCT_2s (t));
4188 if (NULL != t->ephm_h)
4190 LOG (GNUNET_ERROR_TYPE_INFO, " already queued\n");
4194 msg.header.size = htons (sizeof (msg));
4195 msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_AX_KX);
4196 flags = GNUNET_CADET_AX_KX_FLAG_NONE;
4198 flags |= GNUNET_CADET_AX_KX_FLAG_FORCE_REPLY;
4199 msg.flags = htonl (flags);
4200 GNUNET_CRYPTO_ecdhe_key_get_public (t->ax->kx_0, &msg.ephemeral_key);
4201 GNUNET_CRYPTO_ecdhe_key_get_public (t->ax->DHRs, &msg.ratchet_key);
4203 t->ephm_h = send_kx (t, &msg.header);
4204 if (CADET_TUNNEL_KEY_OK != t->estate)
4205 GCT_change_estate (t, CADET_TUNNEL_KEY_SENT);
4210 * Sends an already built and encrypted message on a tunnel, choosing the best
4211 * connection. Useful for re-queueing messages queued on a destroyed connection.
4213 * @param message Message to send. Function modifies it.
4214 * @param t Tunnel on which this message is transmitted.
4217 GCT_resend_message (const struct GNUNET_MessageHeader *message,
4218 struct CadetTunnel *t)
4220 struct CadetConnection *c;
4223 c = tunnel_get_connection (t);
4226 /* TODO queue in tunnel, marked as encrypted */
4227 LOG (GNUNET_ERROR_TYPE_DEBUG, "No connection available, dropping.\n");
4230 fwd = GCC_is_origin (c, GNUNET_YES);
4231 GNUNET_break (NULL == GCC_send_prebuilt_message (message, 0, 0, c, fwd,
4232 GNUNET_YES, NULL, NULL));
4237 * Is the tunnel directed towards the local peer?
4241 * @return #GNUNET_YES if it is loopback.
4244 GCT_is_loopback (const struct CadetTunnel *t)
4246 return (myid == GCP_get_short_id (t->peer));
4251 * Is the tunnel this path already?
4256 * @return #GNUNET_YES a connection uses this path.
4259 GCT_is_path_used (const struct CadetTunnel *t, const struct CadetPeerPath *p)
4261 struct CadetTConnection *iter;
4263 for (iter = t->connection_head; NULL != iter; iter = iter->next)
4264 if (path_equivalent (GCC_get_path (iter->c), p))
4272 * Get a cost of a path for a tunnel considering existing connections.
4275 * @param path Candidate path.
4277 * @return Cost of the path (path length + number of overlapping nodes)
4280 GCT_get_path_cost (const struct CadetTunnel *t,
4281 const struct CadetPeerPath *path)
4283 struct CadetTConnection *iter;
4284 const struct CadetPeerPath *aux;
4285 unsigned int overlap;
4293 GNUNET_assert (NULL != t);
4295 for (i = 0; i < path->length; i++)
4297 for (iter = t->connection_head; NULL != iter; iter = iter->next)
4299 aux = GCC_get_path (iter->c);
4303 for (j = 0; j < aux->length; j++)
4305 if (path->peers[i] == aux->peers[j])
4313 return path->length + overlap;
4318 * Get the static string for the peer this tunnel is directed.
4322 * @return Static string the destination peer's ID.
4325 GCT_2s (const struct CadetTunnel *t)
4330 return GCP_2s (t->peer);
4334 /******************************************************************************/
4335 /***************************** INFO/DEBUG *******************************/
4336 /******************************************************************************/
4339 ax_debug (const struct CadetTunnelAxolotl *ax, enum GNUNET_ErrorType level)
4341 struct GNUNET_CRYPTO_EcdhePublicKey pub;
4342 struct CadetTunnelSkippedKey *iter;
4345 LOG2 (level, "TTT RK\t %s\n",
4346 GNUNET_h2s ((struct GNUNET_HashCode *) &ax->RK));
4348 LOG2 (level, "TTT HKs\t %s\n",
4349 GNUNET_h2s ((struct GNUNET_HashCode *) &ax->HKs));
4350 LOG2 (level, "TTT HKr\t %s\n",
4351 GNUNET_h2s ((struct GNUNET_HashCode *) &ax->HKr));
4352 LOG2 (level, "TTT NHKs\t %s\n",
4353 GNUNET_h2s ((struct GNUNET_HashCode *) &ax->NHKs));
4354 LOG2 (level, "TTT NHKr\t %s\n",
4355 GNUNET_h2s ((struct GNUNET_HashCode *) &ax->NHKr));
4357 LOG2 (level, "TTT CKs\t %s\n",
4358 GNUNET_h2s ((struct GNUNET_HashCode *) &ax->CKs));
4359 LOG2 (level, "TTT CKr\t %s\n",
4360 GNUNET_h2s ((struct GNUNET_HashCode *) &ax->CKr));
4362 GNUNET_CRYPTO_ecdhe_key_get_public (ax->DHRs, &pub);
4363 LOG2 (level, "TTT DHRs\t %s\n",
4364 GNUNET_i2s ((struct GNUNET_PeerIdentity *) &pub));
4365 LOG2 (level, "TTT DHRr\t %s\n",
4366 GNUNET_h2s ((struct GNUNET_HashCode *) &ax->DHRr));
4368 LOG2 (level, "TTT Nr\t %u\tNs\t%u\n", ax->Nr, ax->Ns);
4369 LOG2 (level, "TTT PNs\t %u\tSkipped\t%u\n", ax->PNs, ax->skipped);
4370 LOG2 (level, "TTT Ratchet\t%u\n", ax->ratchet_flag);
4372 for (iter = ax->skipped_head; NULL != iter; iter = iter->next)
4374 LOG2 (level, "TTT HK\t %s\n",
4375 GNUNET_h2s ((struct GNUNET_HashCode *) &iter->HK));
4376 LOG2 (level, "TTT MK\t %s\n",
4377 GNUNET_h2s ((struct GNUNET_HashCode *) &iter->MK));
4382 * Log all possible info about the tunnel state.
4384 * @param t Tunnel to debug.
4385 * @param level Debug level to use.
4388 GCT_debug (const struct CadetTunnel *t, enum GNUNET_ErrorType level)
4390 struct CadetTChannel *iterch;
4391 struct CadetTConnection *iterc;
4394 do_log = GNUNET_get_log_call_status (level & (~GNUNET_ERROR_TYPE_BULK),
4396 __FILE__, __FUNCTION__, __LINE__);
4400 LOG2 (level, "TTT DEBUG TUNNEL TOWARDS %s\n", GCT_2s (t));
4401 LOG2 (level, "TTT cstate %s, estate %s\n",
4402 cstate2s (t->cstate), estate2s (t->estate));
4403 LOG2 (level, "TTT kx_ctx %p, rekey_task %u, finish task %u\n",
4404 t->kx_ctx, t->rekey_task, t->kx_ctx ? t->kx_ctx->finish_task : 0);
4405 #if DUMP_KEYS_TO_STDERR
4406 if (CADET_Axolotl == t->enc_type)
4408 ax_debug (t->ax, level);
4412 LOG2 (level, "TTT my EPHM\t %s\n",
4413 GNUNET_h2s ((struct GNUNET_HashCode *) &otr_kx_msg.ephemeral_key));
4414 LOG2 (level, "TTT peers EPHM:\t %s\n",
4415 GNUNET_h2s ((struct GNUNET_HashCode *) &t->peers_ephemeral_key));
4416 LOG2 (level, "TTT ENC key:\t %s\n",
4417 GNUNET_h2s ((struct GNUNET_HashCode *) &t->e_key));
4418 LOG2 (level, "TTT DEC key:\t %s\n",
4419 GNUNET_h2s ((struct GNUNET_HashCode *) &t->d_key));
4422 LOG2 (level, "TTT OLD ENC key:\t %s\n",
4423 GNUNET_h2s ((struct GNUNET_HashCode *) &t->kx_ctx->e_key_old));
4424 LOG2 (level, "TTT OLD DEC key:\t %s\n",
4425 GNUNET_h2s ((struct GNUNET_HashCode *) &t->kx_ctx->d_key_old));
4429 LOG2 (level, "TTT tq_head %p, tq_tail %p\n", t->tq_head, t->tq_tail);
4430 LOG2 (level, "TTT destroy %u\n", t->destroy_task);
4432 LOG2 (level, "TTT channels:\n");
4433 for (iterch = t->channel_head; NULL != iterch; iterch = iterch->next)
4435 LOG2 (level, "TTT - %s\n", GCCH_2s (iterch->ch));
4438 LOG2 (level, "TTT connections:\n");
4439 for (iterc = t->connection_head; NULL != iterc; iterc = iterc->next)
4441 GCC_debug (iterc->c, level);
4444 LOG2 (level, "TTT DEBUG TUNNEL END\n");
4449 * Iterate all tunnels.
4451 * @param iter Iterator.
4452 * @param cls Closure for @c iter.
4455 GCT_iterate_all (GNUNET_CONTAINER_PeerMapIterator iter, void *cls)
4457 GNUNET_CONTAINER_multipeermap_iterate (tunnels, iter, cls);
4462 * Count all tunnels.
4464 * @return Number of tunnels to remote peers kept by this peer.
4467 GCT_count_all (void)
4469 return GNUNET_CONTAINER_multipeermap_size (tunnels);
4474 * Iterate all connections of a tunnel.
4476 * @param t Tunnel whose connections to iterate.
4477 * @param iter Iterator.
4478 * @param cls Closure for @c iter.
4481 GCT_iterate_connections (struct CadetTunnel *t, GCT_conn_iter iter, void *cls)
4483 struct CadetTConnection *ct;
4485 for (ct = t->connection_head; NULL != ct; ct = ct->next)
4491 * Iterate all channels of a tunnel.
4493 * @param t Tunnel whose channels to iterate.
4494 * @param iter Iterator.
4495 * @param cls Closure for @c iter.
4498 GCT_iterate_channels (struct CadetTunnel *t, GCT_chan_iter iter, void *cls)
4500 struct CadetTChannel *cht;
4502 for (cht = t->channel_head; NULL != cht; cht = cht->next)
4503 iter (cls, cht->ch);